diff options
Diffstat (limited to 'transupp.h')
| -rw-r--r-- | transupp.h | 34 |
1 files changed, 27 insertions, 7 deletions
@@ -2,7 +2,7 @@ * transupp.h * * This file was part of the Independent JPEG Group's software: - * Copyright (C) 1997-2011, Thomas G. Lane, Guido Vollbeding. + * Copyright (C) 1997-2019, Thomas G. Lane, Guido Vollbeding. * libjpeg-turbo Modifications: * Copyright (C) 2017, D. R. Commander. * For conditions of distribution and use, see the accompanying README.ijg @@ -62,6 +62,17 @@ * output image covers at least the requested region, but may cover more.) * The adjustment of the region dimensions may be optionally disabled. * + * A complementary lossless wipe option is provided to discard (gray out) data + * inside a given image region while losslessly preserving what is outside. + * A lossless drop option is also provided, which allows another JPEG image to + * be inserted ("dropped") into the source image data at a given position, + * replacing the existing image data at that position. Both the source image + * and the drop image must have the same subsampling level. It is best if they + * also have the same quantization (quality.) Otherwise, the quantization of + * the output image will be adapted to accommodate the higher of the source + * image quality and the drop image quality. The trim option can be used with + * the drop option to requantize the drop image to match the source image. + * * We also provide a lossless-resize option, which is kind of a lossless-crop * operation in the DCT coefficient block domain - it discards higher-order * coefficients and losslessly preserves lower-order coefficients of a @@ -92,20 +103,23 @@ typedef enum { JXFORM_TRANSVERSE, /* transpose across UR-to-LL axis */ JXFORM_ROT_90, /* 90-degree clockwise rotation */ JXFORM_ROT_180, /* 180-degree rotation */ - JXFORM_ROT_270 /* 270-degree clockwise (or 90 ccw) */ + JXFORM_ROT_270, /* 270-degree clockwise (or 90 ccw) */ + JXFORM_WIPE, /* wipe */ + JXFORM_DROP /* drop */ } JXFORM_CODE; /* * Codes for crop parameters, which can individually be unspecified, * positive or negative for xoffset or yoffset, - * positive or forced for width or height. + * positive or force or reflect for width or height. */ typedef enum { JCROP_UNSET, JCROP_POS, JCROP_NEG, - JCROP_FORCE + JCROP_FORCE, + JCROP_REFLECT } JCROP_CODE; /* @@ -120,7 +134,7 @@ typedef struct { boolean perfect; /* if TRUE, fail if partial MCUs are requested */ boolean trim; /* if TRUE, trim partial MCUs as needed */ boolean force_grayscale; /* if TRUE, convert color image to grayscale */ - boolean crop; /* if TRUE, crop source image */ + boolean crop; /* if TRUE, crop or wipe source image, or drop */ boolean slow_hflip; /* For best performance, the JXFORM_FLIP_H transform normally modifies the source coefficients in place. Setting this to TRUE will instead use a slower, @@ -133,14 +147,18 @@ typedef struct { * These can be filled in by jtransform_parse_crop_spec(). */ JDIMENSION crop_width; /* Width of selected region */ - JCROP_CODE crop_width_set; /* (forced disables adjustment) */ + JCROP_CODE crop_width_set; /* (force-disables adjustment) */ JDIMENSION crop_height; /* Height of selected region */ - JCROP_CODE crop_height_set; /* (forced disables adjustment) */ + JCROP_CODE crop_height_set; /* (force-disables adjustment) */ JDIMENSION crop_xoffset; /* X offset of selected region */ JCROP_CODE crop_xoffset_set; /* (negative measures from right edge) */ JDIMENSION crop_yoffset; /* Y offset of selected region */ JCROP_CODE crop_yoffset_set; /* (negative measures from bottom edge) */ + /* Drop parameters: set by caller for drop request */ + j_decompress_ptr drop_ptr; + jvirt_barray_ptr *drop_coef_arrays; + /* Internal workspace: caller should not touch these */ int num_components; /* # of components in workspace */ jvirt_barray_ptr *workspace_coef_arrays; /* workspace for transformations */ @@ -148,6 +166,8 @@ typedef struct { JDIMENSION output_height; JDIMENSION x_crop_offset; /* destination crop offsets measured in iMCUs */ JDIMENSION y_crop_offset; + JDIMENSION drop_width; /* drop/wipe dimensions measured in iMCUs */ + JDIMENSION drop_height; int iMCU_sample_width; /* destination iMCU size */ int iMCU_sample_height; } jpeg_transform_info; |