This file is indexed.

/usr/include/af/image.h is in libarrayfire-dev 3.3.2+dfsg1-4ubuntu1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
/*******************************************************
 * Copyright (c) 2014, ArrayFire
 * All rights reserved.
 *
 * This file is distributed under 3-clause BSD license.
 * The complete license agreement can be obtained at:
 * http://arrayfire.com/licenses/BSD-3-Clause
 ********************************************************/

#pragma once
#include <af/defines.h>
#include <af/features.h>

#ifdef __cplusplus
namespace af
{
class array;

/**
   C++ Interface for calculating the gradients

   \param[out] dx the gradient along first dimension
   \param[out] dy the gradient along second dimension
   \param[in] in is the input array

   \ingroup calc_func_grad
*/
AFAPI void grad(array& dx, array& dy, const array& in);

/**
    C++ Interface for loading an image

    \param[in] filename is name of file to be loaded
    \param[in] is_color boolean denoting if the image should be loaded as 1 channel or 3 channel
    \return image loaded as \ref af::array()

    \ingroup imageio_func_load
*/
AFAPI array loadImage(const char* filename, const bool is_color=false);

/**
    C++ Interface for saving an image

    \param[in] filename is name of file to be loaded
    \param[in] in is the arrayfire array to be saved as an image

    \ingroup imageio_func_save
*/
AFAPI void saveImage(const char* filename, const array& in);

#if AF_API_VERSION >= 31
/**
    C++ Interface for loading an image from memory

    \param[in] ptr is the location of the image data in memory. This is the pointer
    created by saveImage.
    \return image loaded as \ref af::array()

    \note The pointer used is a void* cast of the FreeImage type FIMEMORY which is
    created using the FreeImage_OpenMemory API. If the user is opening a FreeImage
    stream external to ArrayFire, that pointer can be passed to this function as well.

    \ingroup imagemem_func_load
*/
AFAPI array loadImageMem(const void *ptr);
#endif

#if AF_API_VERSION >= 31
/**
    C++ Interface for saving an image to memory

    \param[in] in is the arrayfire array to be saved as an image
    \param[in] format is the type of image to create in memory. The enum borrows from
    the FREE_IMAGE_FORMAT enum of FreeImage. Other values not included in imageFormat
    but included in FREE_IMAGE_FORMAT can also be passed to this function.

    \return a void* pointer which is a type cast of the FreeImage type FIMEMORY* pointer.

    \note Ensure that \ref deleteImageMem is called on this pointer. Otherwise there will
    be memory leaks

    \ingroup imagemem_func_save
*/
AFAPI void* saveImageMem(const array& in, const imageFormat format = AF_FIF_PNG);
#endif

#if AF_API_VERSION >= 31
/**
    C++ Interface for deleting memory created by \ref saveImageMem or
    \ref af_save_image_memory

    \param[in] ptr is the pointer to the FreeImage stream created by saveImageMem.

    \ingroup imagemem_func_delete
*/
AFAPI void deleteImageMem(void *ptr);
#endif

#if AF_API_VERSION >= 32
/**
    C++ Interface for loading an image as its original type

    This load image function allows you to load images as u8, u16 or f32
    depending on the type of input image as shown by the table below.

     Bits per Color (Gray/RGB/RGBA Bits Per Pixel) | Array Type  | Range
    -----------------------------------------------|-------------|---------------
      8 ( 8/24/32  BPP)                            | u8          | 0 - 255
     16 (16/48/64  BPP)                            | u16         | 0 - 65535
     32 (32/96/128 BPP)                            | f32         | 0 - 1

    \param[in] filename is name of file to be loaded
    \return image loaded as \ref af::array()

    \ingroup imageio_func_load
*/
AFAPI array loadImageNative(const char* filename);
#endif

#if AF_API_VERSION >= 32
/**
    C++ Interface for saving an image without modifications

    This function only accepts u8, u16, f32 arrays. These arrays are saved to
    images without any modifications.

    You must also note that note all image type support 16 or 32 bit images.

    The best options for 16 bit images are PNG, PPM and TIFF.
    The best option for 32 bit images is TIFF.
    These allow lossless storage.

    The images stored have the following properties:

     Array Type  | Bits per Color (Gray/RGB/RGBA Bits Per Pixel) | Range
    -------------|-----------------------------------------------|---------------
     u8          |  8 ( 8/24/32  BPP)                            | 0 - 255
     u16         | 16 (16/48/64  BPP)                            | 0 - 65535
     f32         | 32 (32/96/128 BPP)                            | 0 - 1

    \param[in] filename is name of file to be saved
    \param[in] in is the array to be saved. Should be u8 for saving 8-bit image,
    u16 for 16-bit image, and f32 for 32-bit image.

    \ingroup imageio_func_save
*/
AFAPI void saveImageNative(const char* filename, const array& in);
#endif

#if AF_API_VERSION >= 33
/**
    Function to check if Image IO is available

    \returns true if ArrayFire was commpiled with ImageIO support, false otherwise.
    \ingroup imageio_func_available
*/
AFAPI bool isImageIOAvailable();
#endif

/**
    C++ Interface for resizing an image to specified dimensions

    \param[in] in is input image
    \param[in] odim0 is the size for the first output dimension
    \param[in] odim1 is the size for the second output dimension
    \param[in] method is the interpolation type (Nearest by default)
    \return the resized image of specified by \p odim0 and \p odim1

    \ingroup transform_func_resize
*/
AFAPI array resize(const array& in, const dim_t odim0, const dim_t odim1, const interpType method=AF_INTERP_NEAREST);

/**
    C++ Interface for resizing an image to specified scales

    \param[in] scale0 is scale used for first input dimension
    \param[in] scale1 is scale used for second input dimension
    \param[in] in is input image
    \param[in] method is the interpolation type (Nearest by default)
    \return the image scaled by the specified by \p scale0 and \p scale1

    \ingroup transform_func_resize
*/
AFAPI array resize(const float scale0, const float scale1, const array& in, const interpType method=AF_INTERP_NEAREST);

/**
    C++ Interface for resizing an image to specified scale

    \param[in] scale is scale used for both input dimensions
    \param[in] in is input image
    \param[in] method is the interpolation type (Nearest by default)
    \return the image scaled by the specified by \p scale

    \ingroup transform_func_resize
*/
AFAPI array resize(const float scale, const array& in, const interpType method=AF_INTERP_NEAREST);

/**
    C++ Interface for rotating an image

    \param[in] in is input image
    \param[in] theta is the degree (in radians) by which the input is rotated
    \param[in] crop if true the output is cropped original dimensions. If false the output dimensions scale based on \p theta
    \param[in] method is the interpolation type (Nearest by default)
    \return the image rotated by \p theta

    \ingroup transform_func_rotate
*/
AFAPI array rotate(const array& in, const float theta, const bool crop=true, const interpType method=AF_INTERP_NEAREST);

/**
    C++ Interface for transforming an image

    \param[in] in is input image
    \param[in] transform is transformation matrix
    \param[in] odim0 is the first output dimension
    \param[in] odim1 is the second output dimension
    \param[in] method is the interpolation type (Nearest by default)
    \param[in] inverse if true applies inverse transform, if false applies forward transoform
    \return the transformed image

    \ingroup transform_func_transform
*/
AFAPI array transform(const array& in, const array& transform, const dim_t odim0 = 0, const dim_t odim1 = 0, const interpType method=AF_INTERP_NEAREST, const bool inverse=true);

#if AF_API_VERSION >= 33
/**
    C++ Interface for transforming coordinates

    \param[in] tf is transformation matrix
    \param[in] d0 is the first input dimension
    \param[in] d1 is the second input dimension
    \return the transformed coordinates

    \ingroup transform_func_coordinates
*/
AFAPI array transformCoordinates(const array& tf, const float d0, const float d1);
#endif

/**
    C++ Interface for translating an image

    \param[in] in is input image
    \param[in] trans0 is amount by which the first dimension is translated
    \param[in] trans1 is amount by which the second dimension is translated
    \param[in] odim0 is the first output dimension
    \param[in] odim1 is the second output dimension
    \param[in] method is the interpolation type (Nearest by default)
    \return the translated image

    \ingroup transform_func_translate
*/
AFAPI array translate(const array& in, const float trans0, const float trans1, const dim_t odim0 = 0, const dim_t odim1 = 0, const interpType method=AF_INTERP_NEAREST);

/**
    C++ Interface for scaling an image

    \param[in] in is input image
    \param[in] scale0 is amount by which the first dimension is scaled
    \param[in] scale1 is amount by which the second dimension is scaled
    \param[in] odim0 is the first output dimension
    \param[in] odim1 is the second output dimension
    \param[in] method is the interpolation type (Nearest by default)
    \return the scaled image

    \ingroup transform_func_scale
*/
AFAPI array scale(const array& in, const float scale0, const float scale1, const dim_t odim0 = 0, const dim_t odim1 = 0, const interpType method=AF_INTERP_NEAREST);

/**
    C++ Interface for skewing an image

    \param[in] in is input image
    \param[in] skew0 is amount by which the first dimension is skewed
    \param[in] skew1 is amount by which the second dimension is skewed
    \param[in] odim0 is the first output dimension
    \param[in] odim1 is the second output dimension
    \param[in] inverse if true applies inverse transform, if false applies forward transoform
    \param[in] method is the interpolation type (Nearest by default)
    \return the skewed image

    \ingroup transform_func_skew
*/
AFAPI array skew(const array& in, const float skew0, const float skew1, const dim_t odim0 = 0, const dim_t odim1 = 0, const bool inverse=true, const interpType method=AF_INTERP_NEAREST);

/**
    C++ Interface for bilateral filter

    \param[in]  in array is the input image
    \param[in]  spatial_sigma is the spatial variance parameter that decides the filter window
    \param[in]  chromatic_sigma is the chromatic variance parameter
    \param[in]  is_color indicates if the input \p in is color image or grayscale
    \return     the processed image

    \ingroup image_func_bilateral
*/
AFAPI array bilateral(const array &in, const float spatial_sigma, const float chromatic_sigma, const bool is_color=false);

/**
   C++ Interface for histogram

   \snippet test/histogram.cpp ex_image_hist_minmax

   \param[in]  in is the input array
   \param[in]  nbins  Number of bins to populate between min and max
   \param[in]  minval minimum bin value (accumulates -inf to min)
   \param[in]  maxval minimum bin value (accumulates max to +inf)
   \return     histogram array of type u32

   \ingroup image_func_histogram
 */
AFAPI array histogram(const array &in, const unsigned nbins, const double minval, const double maxval);

/**
   C++ Interface for histogram

   \snippet test/histogram.cpp ex_image_hist_nominmax

   \param[in]  in is the input array
   \param[in]  nbins  Number of bins to populate between min and max
   \return     histogram array of type u32

   \ingroup image_func_histogram
 */
AFAPI array histogram(const array &in, const unsigned nbins);

/**
    C++ Interface for mean shift

    \param[in]  in array is the input image
    \param[in]  spatial_sigma is the spatial variance parameter that decides the filter window
    \param[in]  chromatic_sigma is the chromatic variance parameter
    \param[in]  iter is the number of iterations filter operation is performed
    \param[in]  is_color indicates if the input \p in is color image or grayscale
    \return     the processed image

    \ingroup image_func_mean_shift
*/
AFAPI array meanShift(const array& in, const float spatial_sigma, const float chromatic_sigma, const unsigned iter, const bool is_color=false);

/**
    C++ Interface for median filter

    \snippet test/medfilt.cpp ex_image_medfilt

    \param[in]  in array is the input image
    \param[in]  wind_length is the kernel height
    \param[in]  wind_width is the kernel width
    \param[in]  edge_pad value will decide what happens to border when running
                filter in their neighborhood. It takes one of the values [\ref AF_PAD_ZERO | \ref AF_PAD_SYM]
    \return     the processed image

    \ingroup image_func_medfilt
*/
AFAPI array medfilt(const array& in, const dim_t wind_length = 3, const dim_t wind_width = 3, const borderType edge_pad = AF_PAD_ZERO);

/**
    C++ Interface for minimum filter

    \param[in]  in array is the input image
    \param[in]  wind_length is the kernel height
    \param[in]  wind_width is the kernel width
    \param[in]  edge_pad value will decide what happens to border when running
                filter in their neighborhood. It takes one of the values [\ref AF_PAD_ZERO | \ref AF_PAD_SYM]
    \return     the processed image

    \ingroup image_func_minfilt
*/
AFAPI array minfilt(const array& in, const dim_t wind_length = 3, const dim_t wind_width = 3, const borderType edge_pad = AF_PAD_ZERO);

/**
    C++ Interface for maximum filter

    \param[in]  in array is the input image
    \param[in]  wind_length is the kernel height
    \param[in]  wind_width is the kernel width
    \param[in]  edge_pad value will decide what happens to border when running
                filter in their neighborhood. It takes one of the values [\ref AF_PAD_ZERO | \ref AF_PAD_SYM]
    \return     the processed image

    \ingroup image_func_maxfilt
*/
AFAPI array maxfilt(const array& in, const dim_t wind_length = 3, const dim_t wind_width = 3, const borderType edge_pad = AF_PAD_ZERO);

/**
    C++ Interface for image dilation (max filter)

    \param[in]  in array is the input image
    \param[in]  mask is the neighborhood window
    \return     the dilated image

    \note if \p mask is all ones, this function behaves like max filter

    \ingroup image_func_dilate
*/
AFAPI array dilate(const array& in, const array& mask);

/**
    C++ Interface for 3D image dilation

    \param[in]  in array is the input volume
    \param[in]  mask is the neighborhood delta volume
    \return     the dilated volume

    \ingroup image_func_dilate3d
*/
AFAPI array dilate3(const array& in, const array& mask);

/**
    C++ Interface for image erosion (min filter)

    \param[in]  in array is the input image
    \param[in]  mask is the neighborhood window
    \return     the eroded image

    \note This function can be used as min filter by using a mask of all ones

    \ingroup image_func_erode
*/
AFAPI array erode(const array& in, const array& mask);

/**
    C++ Interface for 3d for image erosion

    \param[in]  in array is the input volume
    \param[in]  mask is the neighborhood delta volume
    \return     the eroded volume

    \ingroup image_func_erode3d
*/
AFAPI array erode3(const array& in, const array& mask);

/**
    C++ Interface for getting regions in an image

    Below given are sample input and output for each type of connectivity value for \p type

    <table border="0">
    <tr>
    <td> Example for \p type == \ref AF_CONNECTIVITY_8 </td>
    <td> Example for \p type == \ref AF_CONNECTIVITY_4 </td>
    </tr>
    <tr>
    <td>
        \snippet test/regions.cpp ex_image_regions
    </td>
    <td>
        \snippet test/regions.cpp ex_image_regions_4conn
    </td>
    </tr>
    </table>

    \param[in]  in array should be binary image of type \ref b8
    \param[in]  connectivity can take one of the following [\ref AF_CONNECTIVITY_4 | \ref AF_CONNECTIVITY_8]
    \param[in]  type is type of output array
    \return     returns array with labels indicating different regions. Throws exceptions if any issue occur.

    \ingroup image_func_regions
*/
AFAPI array regions(const array& in, const af::connectivity connectivity=AF_CONNECTIVITY_4, const dtype type=f32);

/**
   C++ Interface for extracting sobel gradients

   \param[out] dx is derivative along horizontal direction
   \param[out] dy is derivative along vertical direction
   \param[in]  img is an array with image data
   \param[in]  ker_size sobel kernel size or window size

   \note If \p img is 3d array, a batch operation will be performed.

   \ingroup image_func_sobel
 */
AFAPI void sobel(array &dx, array &dy, const array &img, const unsigned ker_size=3);

/**
   C++ Interface for sobel filtering

   \param[in]  img is an array with image data
   \param[in]  ker_size sobel kernel size or window size
   \param[in]  isFast = true uses \f$G=G_x+G_y\f$, otherwise \f$G=\sqrt (G_x^2+G_y^2)\f$
   \return     an array with sobel gradient values

   \note If \p img is 3d array, a batch operation will be performed.

   \ingroup image_func_sobel
 */
AFAPI array sobel(const array &img, const unsigned ker_size=3, const bool isFast=false);

/**
   C++ Interface for RGB to gray conversion

   \param[in]  in is an array in the RGB colorspace
   \param[in]  rPercent is percentage of red channel value contributing to grayscale intensity
   \param[in]  gPercent is percentage of green channel value contributing to grayscale intensity
   \param[in]  bPercent is percentage of blue channel value contributing to grayscale intensity
   \return     array in Grayscale colorspace

   \note \p in must be three dimensional for RGB to Grayscale conversion.

   \ingroup image_func_rgb2gray
 */
AFAPI array rgb2gray(const array& in, const float rPercent=0.2126f, const float gPercent=0.7152f, const float bPercent=0.0722f);

/**
   C++ Interface for gray to RGB conversion

   \param[in]  in is an array in the Grayscale colorspace
   \param[in]  rFactor is percentage of intensity value contributing to red channel
   \param[in]  gFactor is percentage of intensity value contributing to green channel
   \param[in]  bFactor is percentage of intensity value contributing to blue channel
   \return     array in RGB colorspace

   \note \p in must be two dimensional for Grayscale to RGB conversion.

   \ingroup image_func_gray2rgb
 */
AFAPI array gray2rgb(const array& in, const float rFactor=1.0, const float gFactor=1.0, const float bFactor=1.0);

/**
   C++ Interface for histogram equalization

   \snippet test/histogram.cpp ex_image_histequal

   \param[in]  in is the input array, non-normalized input (!! assumes values [0-255] !!)
   \param[in]  hist target histogram to approximate in output (based on number of bins)
   \return     data with histogram approximately equal to histogram

   \note \p in must be two dimensional.

   \ingroup image_func_histequal
 */
AFAPI array histEqual(const array& in, const array& hist);

/**
   C++ Interface for generating gausian kernels

   \param[in]  rows number of rows of the kernel
   \param[in]  cols number of columns of the kernel
   \param[in]  sig_r (default 0) (calculated internally as 0.25 * rows + 0.75)
   \param[in]  sig_c (default 0) (calculated internally as 0.25 * cols + 0.75)
   \return     an array with values generated using gaussian function

   \ingroup image_func_gauss
 */
AFAPI array gaussianKernel(const int rows, const int cols, const double sig_r = 0, const double sig_c = 0);

/**
   C++ Interface for converting HSV to RGB

   \param[in]  in is an array in the HSV colorspace
   \return     array in RGB colorspace

   \note \p in must be three dimensional

   \ingroup image_func_hsv2rgb
 */
AFAPI array hsv2rgb(const array& in);

/**
   C++ Interface for converting RGB to HSV

   \param[in]  in is an array in the RGB colorspace
   \return     array in HSV colorspace

   \note \p in must be three dimensional

   \ingroup image_func_rgb2hsv
 */
AFAPI array rgb2hsv(const array& in);

/**
   C++ Interface wrapper for colorspace conversion

   \param[in]  image is the input array
   \param[in]  to is the target array colorspace
   \param[in]  from is the input array colorspace
   \return     array in target colorspace

   \note  \p image must be 3 dimensional for \ref AF_HSV to \ref AF_RGB, \ref AF_RGB to
   \ref AF_HSV, & \ref AF_RGB to \ref AF_GRAY transformations. For \ref AF_GRAY to \ref AF_RGB
   transformation, 2D array is expected.

   \ingroup image_func_colorspace
 */
AFAPI array colorSpace(const array& image, const CSpace to, const CSpace from);

#if AF_API_VERSION >= 31
/**
   C++ Interface wrapper for unwrap

   \param[in]  in is the input image (or set of images)
   \param[in]  wx is the block window size along 0th-dimension between [1, input.dims[0] + px]
   \param[in]  wy is the block window size along 1st-dimension between [1, input.dims[1] + py]
   \param[in]  sx is the stride along 0th-dimension
   \param[in]  sy is the stride along 1st-dimension
   \param[in]  px is the padding along 0th-dimension between [0, wx). Padding is applied both before and after.
   \param[in]  py is the padding along 1st-dimension between [0, wy). Padding is applied both before and after.
   \param[in]  is_column specifies the layout for the unwrapped patch. If is_column is false, the unrapped patch is laid out as a row.
   \returns    an array with the image blocks as rows or columns

   \ingroup image_func_unwrap
*/
AFAPI array unwrap(const array& in, const dim_t wx, const dim_t wy,
                   const dim_t sx, const dim_t sy, const dim_t px=0, const dim_t py=0,
                   const bool is_column = true);
#endif

#if AF_API_VERSION >= 31
/**
   C++ Interface wrapper for wrap

   \param[in]  in is the input image (or set of images)
   \param[in]  ox is the 0th-dimension of output
   \param[in]  oy is the ist-dimension of output
   \param[in]  wx is the block window size along 0th-dimension between
   \param[in]  wy is the block window size along 1st-dimension between
   \param[in]  sx is the stride along 0th-dimension
   \param[in]  sy is the stride along 1st-dimension
   \param[in]  px is the padding used along 0th-dimension between [0, wx).
   \param[in]  py is the padding used along 1st-dimension between [0, wy).
   \param[in]  is_column specifies the layout for the unwrapped patch. If is_column is false, the rows are treated as patches
   \returns    an array of images after converting rows or columns into image windows

   \ingroup image_func_wrap
*/
AFAPI array wrap(const array& in,
                 const dim_t ox, const dim_t oy,
                 const dim_t wx, const dim_t wy,
                 const dim_t sx, const dim_t sy,
                 const dim_t px = 0, const dim_t py = 0,
                 const bool is_column = true);
#endif

#if AF_API_VERSION >= 31
/**
   C++ Interface wrapper for summed area tables

   \param[in]  in is the input array
   \returns the summed area table of input image

   \ingroup image_func_sat
*/
AFAPI array sat(const array& in);
#endif

#if AF_API_VERSION >= 31
/**
   C++ Interface for converting YCbCr to RGB

   \param[in]  in is an array in the YCbCr colorspace
   \param[in]  standard specifies the ITU-R BT "xyz" standard which determines the Kb, Kr values
   used in colorspace conversion equation
   \return     array in RGB colorspace

   \note \p in must be three dimensional and values should lie in the range [0,1]

   \ingroup image_func_ycbcr2rgb
 */
AFAPI array ycbcr2rgb(const array& in, const YCCStd standard=AF_YCC_601);
#endif

#if AF_API_VERSION >= 31
/**
   C++ Interface for converting RGB to YCbCr

   \param[in]  in is an array in the RGB colorspace
   \param[in]  standard specifies the ITU-R BT "xyz" standard which determines the Kb, Kr values
   used in colorspace conversion equation
   \return     array in YCbCr colorspace

   \note \p in must be three dimensional and values should lie in the range [0,1]

   \ingroup image_func_rgb2ycbcr
 */
AFAPI array rgb2ycbcr(const array& in, const YCCStd standard=AF_YCC_601);
#endif

}
#endif

#ifdef __cplusplus
extern "C" {
#endif

    /**
        C Interface for calculating the gradients

        \param[out] dx the gradient along first dimension
        \param[out] dy the gradient along second dimension
        \param[in]  in is the input array
        \return     \ref AF_SUCCESS if the color transformation is successful,
        otherwise an appropriate error code is returned.

        \ingroup calc_func_grad
    */
    AFAPI af_err af_gradient(af_array *dx, af_array *dy, const af_array in);

    /**
        C Interface for loading an image

        \param[out] out will contain the image
        \param[in] filename is name of file to be loaded
        \param[in] isColor boolean denoting if the image should be loaded as 1 channel or 3 channel
        \return     \ref AF_SUCCESS if the color transformation is successful,
        otherwise an appropriate error code is returned.

        \ingroup imageio_func_load
    */
    AFAPI af_err af_load_image(af_array *out, const char* filename, const bool isColor);

    /**
        C Interface for saving an image

        \param[in] filename is name of file to be loaded
        \param[in] in is the arrayfire array to be saved as an image
        \return     \ref AF_SUCCESS if the color transformation is successful,
        otherwise an appropriate error code is returned.

        \ingroup imageio_func_save
    */
    AFAPI af_err af_save_image(const char* filename, const af_array in);

#if AF_API_VERSION >= 31
    /**
        C Interface for loading an image from memory

        \param[out] out is an array that will contain the image
        \param[in] ptr is the FIMEMORY pointer created by either saveImageMem function, the
        af_save_image_memory function, or the FreeImage_OpenMemory API.
        \return     \ref AF_SUCCESS if successful

        \ingroup imagemem_func_load
    */
    AFAPI af_err af_load_image_memory(af_array *out, const void* ptr);
#endif

#if AF_API_VERSION >= 31
    /**
        C Interface for saving an image to memory using FreeImage

        \param[out] ptr is the FIMEMORY pointer created by FreeImage.
        \param[in] in is the arrayfire array to be saved as an image
        \param[in] format is the type of image to create in memory. The enum borrows from
        the FREE_IMAGE_FORMAT enum of FreeImage. Other values not included in af_image_format
        but included in FREE_IMAGE_FORMAT can also be passed to this function.
        \return     \ref AF_SUCCESS if successful.

        \ingroup imagemem_func_save
    */
    AFAPI af_err af_save_image_memory(void** ptr, const af_array in, const af_image_format format);
#endif

#if AF_API_VERSION >= 31
    /**
        C Interface for deleting an image from memory

        \param[in] ptr is the FIMEMORY pointer created by either saveImageMem function, the
        af_save_image_memory function, or the FreeImage_OpenMemory API.
        \return     \ref AF_SUCCESS if successful

        \ingroup imagemem_func_delete
    */
    AFAPI af_err af_delete_image_memory(void* ptr);
#endif

#if AF_API_VERSION >= 32
    /**
        C Interface for loading an image as is original type

        This load image function allows you to load images as u8, u16 or f32
        depending on the type of input image as shown by the table below.

         Bits per Color (Gray/RGB/RGBA Bits Per Pixel) | Array Type  | Range
        -----------------------------------------------|-------------|---------------
          8 ( 8/24/32  BPP)                            | u8          | 0 - 255
         16 (16/48/64  BPP)                            | u16         | 0 - 65535
         32 (32/96/128 BPP)                            | f32         | 0 - 1

        \param[out] out contains them image
        \param[in] filename is name of file to be loaded
        \return     \ref AF_SUCCESS if successful

        \ingroup imageio_func_load
    */
    AFAPI af_err af_load_image_native(af_array *out, const char* filename);
#endif

#if AF_API_VERSION >= 32
    /**
        C Interface for saving an image without modifications

        This function only accepts u8, u16, f32 arrays. These arrays are saved to
        images without any modifications.

        You must also note that note all image type support 16 or 32 bit images.

        The best options for 16 bit images are PNG, PPM and TIFF.
        The best option for 32 bit images is TIFF.
        These allow lossless storage.

        The images stored have the following properties:

         Array Type  | Bits per Color (Gray/RGB/RGBA Bits Per Pixel) | Range
        -------------|-----------------------------------------------|---------------
         u8          |  8 ( 8/24/32  BPP)                            | 0 - 255
         u16         | 16 (16/48/64  BPP)                            | 0 - 65535
         f32         | 32 (32/96/128 BPP)                            | 0 - 1

        \param[in] filename is name of file to be saved
        \param[in] in is the array to be saved. Should be u8 for saving 8-bit image,
        u16 for 16-bit image, and f32 for 32-bit image.

        \return     \ref AF_SUCCESS if successful

        \ingroup imageio_func_save
    */
    AFAPI af_err af_save_image_native(const char* filename, const af_array in);
#endif

#if AF_API_VERSION >= 33
    /**
        Function to check if Image IO is available

        \param[out] out is true if ArrayFire was commpiled with ImageIO support,
        false otherwise.

        \return     \ref AF_SUCCESS if successful

        \ingroup imageio_func_available
    */
    AFAPI af_err af_is_image_io_available(bool *out);
#endif

    /**
       C Interface for resizing an image to specified dimensions

       \param[out] out will contain the resized image of specified by \p odim0 and \p odim1
       \param[in] in is input image
       \param[in] odim0 is the size for the first output dimension
       \param[in] odim1 is the size for the second output dimension
       \param[in] method is the interpolation type (Nearest by default)

       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \ingroup transform_func_resize
    */
    AFAPI af_err af_resize(af_array *out, const af_array in, const dim_t odim0, const dim_t odim1, const af_interp_type method);

    /**
       C Interface for transforming an image

       \param[out] out will contain the transformed image
       \param[in] in is input image
       \param[in] transform is transformation matrix
       \param[in] odim0 is the first output dimension
       \param[in] odim1 is the second output dimension
       \param[in] method is the interpolation type (Nearest by default)
       \param[in] inverse if true applies inverse transform, if false applies forward transoform
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \ingroup transform_func_transform
    */
    AFAPI af_err af_transform(af_array *out, const af_array in, const af_array transform,
                              const dim_t odim0, const dim_t odim1,
                              const af_interp_type method, const bool inverse);

#if AF_API_VERSION >= 33
    /**
       C Interface for transforming an image
       C++ Interface for transforming coordinates

       \param[out] out the transformed coordinates
       \param[in] tf is transformation matrix
       \param[in] d0 is the first input dimension
       \param[in] d1 is the second input dimension

       \ingroup transform_func_coordinates
    */
    AFAPI af_err af_transform_coordinates(af_array *out, const af_array tf, const float d0, const float d1);
#endif

    /**
       C Interface for rotating an image

       \param[out] out will contain the image \p in rotated by \p theta
       \param[in] in is input image
       \param[in] theta is the degree (in radians) by which the input is rotated
       \param[in] crop if true the output is cropped original dimensions. If false the output dimensions scale based on \p theta
       \param[in] method is the interpolation type (Nearest by default)
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \ingroup transform_func_rotate
    */
    AFAPI af_err af_rotate(af_array *out, const af_array in, const float theta,
                           const bool crop, const af_interp_type method);
   /**
      C Interface for translate an image

      \param[out] out will contain the translated image
      \param[in] in is input image
      \param[in] trans0 is amount by which the first dimension is translated
      \param[in] trans1 is amount by which the second dimension is translated
      \param[in] odim0 is the first output dimension
      \param[in] odim1 is the second output dimension
      \param[in] method is the interpolation type (Nearest by default)
      \return     \ref AF_SUCCESS if the color transformation is successful,
      otherwise an appropriate error code is returned.

      \ingroup transform_func_translate
   */
    AFAPI af_err af_translate(af_array *out, const af_array in, const float trans0, const float trans1,
                              const dim_t odim0, const dim_t odim1, const af_interp_type method);
    /**
       C Interface for scaling an image

       \param[out] out will contain the scaled image
       \param[in] in is input image
       \param[in] scale0 is amount by which the first dimension is scaled
       \param[in] scale1 is amount by which the second dimension is scaled
       \param[in] odim0 is the first output dimension
       \param[in] odim1 is the second output dimension
       \param[in] method is the interpolation type (Nearest by default)
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \ingroup transform_func_scale
    */
    AFAPI af_err af_scale(af_array *out, const af_array in, const float scale0, const float scale1,
                          const dim_t odim0, const dim_t odim1, const af_interp_type method);
    /**
       C Interface for skewing an image

       \param[out] out will contain the skewed image
       \param[in] in is input image
       \param[in] skew0 is amount by which the first dimension is skewed
       \param[in] skew1 is amount by which the second dimension is skewed
       \param[in] odim0 is the first output dimension
       \param[in] odim1 is the second output dimension
       \param[in] inverse if true applies inverse transform, if false applies forward transoform
       \param[in] method is the interpolation type (Nearest by default)
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \ingroup transform_func_skew
    */
    AFAPI af_err af_skew(af_array *out, const af_array in, const float skew0, const float skew1,
                         const dim_t odim0, const dim_t odim1, const af_interp_type method,
                         const bool inverse);

    /**
       C Interface for histogram

       \param[out] out (type u32) is the histogram for input array in
       \param[in]  in is the input array
       \param[in]  nbins  Number of bins to populate between min and max
       \param[in]  minval minimum bin value (accumulates -inf to min)
       \param[in]  maxval minimum bin value (accumulates max to +inf)
       \return     \ref AF_SUCCESS if the histogram is successfully created,
       otherwise an appropriate error code is returned.

       \ingroup image_func_histogram
     */
    AFAPI af_err af_histogram(af_array *out, const af_array in, const unsigned nbins, const double minval, const double maxval);

    /**
        C Interface for image dilation (max filter)

        \param[out] out array is the dilated image
        \param[in]  in array is the input image
        \param[in]  mask is the neighborhood window
        \return     \ref AF_SUCCESS if the dilated successfully,
        otherwise an appropriate error code is returned.

        \note if \p mask is all ones, this function behaves like max filter

        \ingroup image_func_dilate
    */
    AFAPI af_err af_dilate(af_array *out, const af_array in, const af_array mask);

    /**
        C Interface for 3d image dilation

        \param[out] out array is the dilated volume
        \param[in]  in array is the input volume
        \param[in]  mask is the neighborhood delta volume
        \return     \ref AF_SUCCESS if the dilated successfully,
        otherwise an appropriate error code is returned.

        \ingroup image_func_dilate3d
    */
    AFAPI af_err af_dilate3(af_array *out, const af_array in, const af_array mask);

    /**
        C Interface for image erosion (min filter)

        \param[out] out array is the eroded image
        \param[in]  in array is the input image
        \param[in]  mask is the neighborhood window
        \return     \ref AF_SUCCESS if the eroded successfully,
        otherwise an appropriate error code is returned.

        \note if \p mask is all ones, this function behaves like min filter

        \ingroup image_func_erode
    */
    AFAPI af_err af_erode(af_array *out, const af_array in, const af_array mask);

    /**
        C Interface for 3D image erosion

        \param[out] out array is the eroded volume
        \param[in]  in array is the input volume
        \param[in]  mask is the neighborhood delta volume
        \return     \ref AF_SUCCESS if the eroded successfully,
        otherwise an appropriate error code is returned.

        \ingroup image_func_erode3d
    */
    AFAPI af_err af_erode3(af_array *out, const af_array in, const af_array mask);

    /**
        C Interface for bilateral filter

        \param[out] out array is the processed image
        \param[in]  in array is the input image
        \param[in]  spatial_sigma is the spatial variance parameter that decides the filter window
        \param[in]  chromatic_sigma is the chromatic variance parameter
        \param[in]  isColor indicates if the input \p in is color image or grayscale
        \return     \ref AF_SUCCESS if the filter is applied successfully,
        otherwise an appropriate error code is returned.

        \ingroup image_func_bilateral
    */
    AFAPI af_err af_bilateral(af_array *out, const af_array in, const float spatial_sigma, const float chromatic_sigma, const bool isColor);

    /**
        C Interface for mean shift

        \param[out] out array is the processed image
        \param[in]  in array is the input image
        \param[in]  spatial_sigma is the spatial variance parameter that decides the filter window
        \param[in]  chromatic_sigma is the chromatic variance parameter
        \param[in]  iter is the number of iterations filter operation is performed
        \param[in]  is_color indicates if the input \p in is color image or grayscale
        \return     \ref AF_SUCCESS if the filter is applied successfully,
        otherwise an appropriate error code is returned.

        \ingroup image_func_mean_shift
    */
    AFAPI af_err af_mean_shift(af_array *out, const af_array in, const float spatial_sigma, const float chromatic_sigma, const unsigned iter, const bool is_color);

    /**
        C Interface for median filter

        \param[out] out array is the processed image
        \param[in]  in array is the input image
        \param[in]  wind_length is the kernel height
        \param[in]  wind_width is the kernel width
        \param[in]  edge_pad value will decide what happens to border when running
                    filter in their neighborhood. It takes one of the values [\ref AF_PAD_ZERO | \ref AF_PAD_SYM]
        \return     \ref AF_SUCCESS if the median filter is applied successfully,
        otherwise an appropriate error code is returned.

        \ingroup image_func_medfilt
    */
    AFAPI af_err af_medfilt(af_array *out, const af_array in, const dim_t wind_length, const dim_t wind_width, const af_border_type edge_pad);

    /**
        C Interface for minimum filter

        \param[out] out array is the processed image
        \param[in]  in array is the input image
        \param[in]  wind_length is the kernel height
        \param[in]  wind_width is the kernel width
        \param[in]  edge_pad value will decide what happens to border when running
                    filter in their neighborhood. It takes one of the values [\ref AF_PAD_ZERO | \ref AF_PAD_SYM]
        \return     \ref AF_SUCCESS if the minimum filter is applied successfully,
        otherwise an appropriate error code is returned.

        \ingroup image_func_minfilt
    */
    AFAPI af_err af_minfilt(af_array *out, const af_array in, const dim_t wind_length, const dim_t wind_width, const af_border_type edge_pad);

    /**
       C Interface for maximum filter

       \param[out] out array is the processed image
       \param[in]  in array is the input image
       \param[in]  wind_length is the kernel height
       \param[in]  wind_width is the kernel width
       \param[in]  edge_pad value will decide what happens to border when running
       filter in their neighborhood. It takes one of the values [\ref AF_PAD_ZERO | \ref AF_PAD_SYM]
       \return     \ref AF_SUCCESS if the maximum filter is applied successfully,
       otherwise an appropriate error code is returned.

       \ingroup image_func_maxfilt
    */
    AFAPI af_err af_maxfilt(af_array *out, const af_array in, const dim_t wind_length, const dim_t wind_width, const af_border_type edge_pad);

    /**
        C Interface for regions in an image

        \param[out] out array will have labels indicating different regions
        \param[in]  in array should be binary image of type \ref b8
        \param[in]  connectivity can take one of the following [\ref AF_CONNECTIVITY_4 | \ref AF_CONNECTIVITY_8]
        \param[in]  ty is type of output array
        \return     \ref AF_SUCCESS if the regions are identified successfully,
        otherwise an appropriate error code is returned.

        \ingroup image_func_regions
    */
    AFAPI af_err af_regions(af_array *out, const af_array in, const af_connectivity connectivity, const af_dtype ty);

    /**
       C Interface for getting sobel gradients

       \param[out] dx is derivative along horizontal direction
       \param[out] dy is derivative along vertical direction
       \param[in]  img is an array with image data
       \param[in]  ker_size sobel kernel size or window size
       \return     \ref AF_SUCCESS if sobel derivatives are computed successfully,
       otherwise an appropriate error code is returned.

       \note If \p img is 3d array, a batch operation will be performed.

       \ingroup image_func_sobel
    */
    AFAPI af_err af_sobel_operator(af_array *dx, af_array *dy, const af_array img, const unsigned ker_size);

    /**
       C Interface for converting RGB to gray

       \param[out] out is an array in target color space
       \param[in]  in is an array in the RGB color space
       \param[in]  rPercent is percentage of red channel value contributing to grayscale intensity
       \param[in]  gPercent is percentage of green channel value contributing to grayscale intensity
       \param[in]  bPercent is percentage of blue channel value contributing to grayscale intensity
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \note \p in must be three dimensional for RGB to Grayscale conversion.

       \ingroup image_func_rgb2gray
    */
    AFAPI af_err af_rgb2gray(af_array* out, const af_array in, const float rPercent, const float gPercent, const float bPercent);

    /**
       C Interface for converting gray to RGB

       \param[out] out is an array in target color space
       \param[in]  in is an array in the Grayscale color space
       \param[in]  rFactor is percentage of intensity value contributing to red channel
       \param[in]  gFactor is percentage of intensity value contributing to green channel
       \param[in]  bFactor is percentage of intensity value contributing to blue channel
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \note \p in must be two dimensional for Grayscale to RGB conversion.

       \ingroup image_func_gray2rgb
    */
    AFAPI af_err af_gray2rgb(af_array* out, const af_array in, const float rFactor, const float gFactor, const float bFactor);

    /**
       C Interface for histogram equalization

       \param[out] out is an array with data that has histogram approximately equal to histogram
       \param[in]  in is the input array, non-normalized input (!! assumes values [0-255] !!)
       \param[in]  hist target histogram to approximate in output (based on number of bins)
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \note \p in must be two dimensional.

       \ingroup image_func_histequal
    */
    AFAPI af_err af_hist_equal(af_array *out, const af_array in, const af_array hist);

    /**
       C Interface generating gaussian kernels

       \param[out] out is an array with values generated using gaussian function
       \param[in]  rows number of rows of the gaussian kernel
       \param[in]  cols number of columns of the gaussian kernel
       \param[in]  sigma_r (default 0) (calculated internally as 0.25 * rows + 0.75)
       \param[in]  sigma_c (default 0) (calculated internally as 0.25 * cols + 0.75)
       \return     \ref AF_SUCCESS if gaussian distribution values are generated successfully,
       otherwise an appropriate error code is returned.

       \ingroup image_func_gauss
    */
    AFAPI af_err af_gaussian_kernel(af_array *out,
                                    const int rows, const int cols,
                                    const double sigma_r, const double sigma_c);

    /**
       C Interface for converting HSV to RGB

       \param[out] out is an array in the RGB color space
       \param[in]  in is an array in the HSV color space
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \note \p in must be three dimensional

       \ingroup image_func_hsv2rgb
    */
    AFAPI af_err af_hsv2rgb(af_array* out, const af_array in);

    /**
       C Interface for converting RGB to HSV

       \param[out] out is an array in the HSV color space
       \param[in]  in is an array in the RGB color space
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \note \p in must be three dimensional

       \ingroup image_func_rgb2hsv
    */
    AFAPI af_err af_rgb2hsv(af_array* out, const af_array in);

    /**
       C Interface wrapper for color space conversion

       \param[out] out is an array in target color space
       \param[in]  image is the input array
       \param[in]  to is the target array color space \param[in]
       from is the input array color space
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code
       is returned.

       \note  \p image must be 3 dimensional for \ref AF_HSV to \ref AF_RGB, \ref
       AF_RGB to \ref AF_HSV, & \ref AF_RGB to \ref AF_GRAY transformations.
       For \ref AF_GRAY to \ref AF_RGB transformation, 2D array is expected.

       \ingroup image_func_colorspace
    */
    AFAPI af_err af_color_space(af_array *out, const af_array image, const af_cspace_t to, const af_cspace_t from);

#if AF_API_VERSION >= 31
    /**
       C Interface wrapper for unwrap

       \param[out] out is an array with image blocks as rows or columns.
       \param[in]  in is the input image (or set of images)
       \param[in]  wx is the block window size along 0th-dimension between [1, input.dims[0] + px]
       \param[in]  wy is the block window size along 1st-dimension between [1, input.dims[1] + py]
       \param[in]  sx is the stride along 0th-dimension
       \param[in]  sy is the stride along 1st-dimension
       \param[in]  px is the padding along 0th-dimension between [0, wx). Padding is applied both before and after.
       \param[in]  py is the padding along 1st-dimension between [0, wy). Padding is applied both before and after.
       \param[in]  is_column specifies the layout for the unwrapped patch. If is_column is false, the unrapped patch is laid out as a row.
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \ingroup image_func_unwrap
    */
    AFAPI af_err af_unwrap(af_array *out, const af_array in, const dim_t wx, const dim_t wy,
                           const dim_t sx, const dim_t sy, const dim_t px, const dim_t py,
                           const bool is_column);
#endif

#if AF_API_VERSION >= 31
    /**
       C Interface wrapper for wrap

       \param[out] out is an array after converting
       \param[in]  in is the input array
       \param[in]  ox is the 0th-dimension of \p out
       \param[in]  oy is the ist-dimension of \p out
       \param[in]  wx is the block window size along 0th-dimension between
       \param[in]  wy is the block window size along 1st-dimension between
       \param[in]  sx is the stride along 0th-dimension
       \param[in]  sy is the stride along 1st-dimension
       \param[in]  px is the padding used along 0th-dimension between [0, wx).
       \param[in]  py is the padding used along 1st-dimension between [0, wy).
       \param[in]  is_column specifies the layout for the unwrapped patch. If is_column is false, the rows are treated as the patches
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \note The padding used in \ref af_unwrap is calculated from the provided parameters

       \ingroup image_func_wrap
    */
    AFAPI af_err af_wrap(af_array *out,
                         const af_array in,
                         const dim_t ox, const dim_t oy,
                         const dim_t wx, const dim_t wy,
                         const dim_t sx, const dim_t sy,
                         const dim_t px, const dim_t py,
                         const bool is_column);
#endif

#if AF_API_VERSION >= 31
    /**
       C Interface wrapper for summed area tables

       \param[out] out is the summed area table on input image(s)
       \param[in]  in is the input array
       \return \ref AF_SUCCESS if the sat computation is successful,
       otherwise an appropriate error code is returned.

       \ingroup image_func_sat
    */
    AFAPI af_err af_sat(af_array *out, const af_array in);
#endif

#if AF_API_VERSION >= 31
    /**
       C Interface for converting YCbCr to RGB

       \param[out] out is an array in the RGB color space
       \param[in]  in is an array in the YCbCr color space
       \param[in]  standard specifies the ITU-R BT "xyz" standard which determines the Kb, Kr values
       used in colorspace conversion equation
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \note \p in must be three dimensional and values should lie in the range [0,1]

       \ingroup image_func_ycbcr2rgb
    */
    AFAPI af_err af_ycbcr2rgb(af_array* out, const af_array in, const af_ycc_std standard);
#endif

#if AF_API_VERSION >= 31
    /**
       C Interface for converting RGB to YCbCr

       \param[out] out is an array in the YCbCr color space
       \param[in]  in is an array in the RGB color space
       \param[in]  standard specifies the ITU-R BT "xyz" standard which determines the Kb, Kr values
       used in colorspace conversion equation
       \return     \ref AF_SUCCESS if the color transformation is successful,
       otherwise an appropriate error code is returned.

       \note \p in must be three dimensional and values should lie in the range [0,1]

       \ingroup image_func_rgb2ycbcr
    */
    AFAPI af_err af_rgb2ycbcr(af_array* out, const af_array in, const af_ycc_std standard);
#endif
#ifdef __cplusplus
}
#endif