1ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 2ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik/* pnginfo.h - header file for PNG reference library 3ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * 4ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * Copyright (c) 1998-2013 Glenn Randers-Pehrson 5ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) 6ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) 7ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * 8ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * Last changed in libpng 1.6.1 [March 28, 2013] 9ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * 10ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * This code is released under the libpng license. 11ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * For conditions of distribution and use, see the disclaimer 12ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * and license in png.h 13ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 14ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 15ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* png_info is a structure that holds the information in a PNG file so 16ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * that the application can find out the characteristics of the image. 17ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * If you are reading the file, this structure will tell you what is 18ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * in the PNG file. If you are writing the file, fill in the information 19ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * you want to put into the PNG file, using png_set_*() functions, then 20ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * call png_write_info(). 21ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * 22ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * The names chosen should be very close to the PNG specification, so 23ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * consult that document for information about the meaning of each field. 24ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * 25ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * With libpng < 0.95, it was only possible to directly set and read the 26ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * the values in the png_info_struct, which meant that the contents and 27ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * order of the values had to remain fixed. With libpng 0.95 and later, 28ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * however, there are now functions that abstract the contents of 29ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * png_info_struct from the application, so this makes it easier to use 30ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * libpng with dynamic libraries, and even makes it possible to use 31ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * libraries that don't have all of the libpng ancillary chunk-handing 32ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * functionality. In libpng-1.5.0 this was moved into a separate private 33ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * file that is not visible to applications. 34ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * 35ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * The following members may have allocated storage attached that should be 36ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * cleaned up before the structure is discarded: palette, trans, text, 37ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile, 38ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these 39ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * are automatically freed when the info structure is deallocated, if they were 40ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * allocated internally by libpng. This behavior can be changed by means 41ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * of the png_data_freer() function. 42ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * 43ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * More allocation details: all the chunk-reading functions that 44ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * change these members go through the corresponding png_set_* 45ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * functions. A function to clear these members is available: see 46ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * png_free_data(). The png_set_* functions do not depend on being 47ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * able to point info structure members to any of the storage they are 48ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * passed (they make their own copies), EXCEPT that the png_set_text 49ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * functions use the same storage passed to them in the text_ptr or 50ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns 51ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * functions do not make their own copies. 52ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 53ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifndef PNGINFO_H 54ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#define PNGINFO_H 55ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 56ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craikstruct png_info_def 57ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik{ 58ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The following are necessary for every PNG file */ 59ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_uint_32 width; /* width of image in pixels (from IHDR) */ 60ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_uint_32 height; /* height of image in pixels (from IHDR) */ 61ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */ 62ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_size_t rowbytes; /* bytes needed to hold an untransformed row */ 63ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */ 64ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */ 65ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_uint_16 num_trans; /* number of transparent palette color (tRNS) */ 66ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */ 67ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */ 68ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The following three should have been named *_method not *_type */ 69ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */ 70ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */ 71ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ 72ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 73ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The following are set by png_set_IHDR, called from the application on 74ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * write, but the are never actually used by the write code. 75ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 76ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */ 77ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte pixel_depth; /* number of bits per pixel */ 78ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte spare_byte; /* to align the data, and for future use */ 79ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 80ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_READ_SUPPORTED 81ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* This is never set during write */ 82ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte signature[8]; /* magic bytes read by libpng from start of file */ 83ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 84ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 85ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The rest of the data is optional. If you are reading, check the 86ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * valid field to see if the information in these are valid. If you 87ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * are writing, set the valid field to those chunks you want written, 88ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * and initialize the appropriate fields below. 89ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 90ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 91ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED) 92ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* png_colorspace only contains 'flags' if neither GAMMA or COLORSPACE are 93ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * defined. When COLORSPACE is switched on all the colorspace-defining 94ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * chunks should be enabled, when GAMMA is switched on all the gamma-defining 95ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * chunks should be enabled. If this is not done it becomes possible to read 96ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * inconsistent PNG files and assign a probably incorrect interpretation to 97ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * the information. (In other words, by carefully choosing which chunks to 98ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * recognize the system configuration can select an interpretation for PNG 99ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * files containing ambiguous data and this will result in inconsistent 100ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * behavior between different libpng builds!) 101ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 102ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_colorspace colorspace; 103ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 104ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 105ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_iCCP_SUPPORTED 106ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* iCCP chunk data. */ 107ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_charp iccp_name; /* profile name */ 108ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_bytep iccp_profile; /* International Color Consortium profile data */ 109ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_uint_32 iccp_proflen; /* ICC profile data length */ 110ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 111ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 112ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_TEXT_SUPPORTED 113ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The tEXt, and zTXt chunks contain human-readable textual data in 114ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * uncompressed, compressed, and optionally compressed forms, respectively. 115ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * The data in "text" is an array of pointers to uncompressed, 116ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * null-terminated C strings. Each chunk has a keyword that describes the 117ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * textual data contained in that chunk. Keywords are not required to be 118ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * unique, and the text string may be empty. Any number of text chunks may 119ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * be in an image. 120ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 121ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik int num_text; /* number of comments read or comments to write */ 122ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik int max_text; /* current size of text array */ 123ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_textp text; /* array of comments read or comments to write */ 124ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif /* PNG_TEXT_SUPPORTED */ 125ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 126ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_tIME_SUPPORTED 127ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The tIME chunk holds the last time the displayed image data was 128ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * modified. See the png_time struct for the contents of this struct. 129ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 130ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_time mod_time; 131ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 132ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 133ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_sBIT_SUPPORTED 134ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The sBIT chunk specifies the number of significant high-order bits 135ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * in the pixel data. Values are in the range [1, bit_depth], and are 136ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * only specified for the channels in the pixel data. The contents of 137ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * the low-order bits is not specified. Data is valid if 138ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * (valid & PNG_INFO_sBIT) is non-zero. 139ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 140ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_color_8 sig_bit; /* significant bits in color channels */ 141ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 142ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 143ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \ 144ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craikdefined(PNG_READ_BACKGROUND_SUPPORTED) 145ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The tRNS chunk supplies transparency data for paletted images and 146ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * other image types that don't need a full alpha channel. There are 147ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * "num_trans" transparency values for a paletted image, stored in the 148ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * same order as the palette colors, starting from index 0. Values 149ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * for the data are in the range [0, 255], ranging from fully transparent 150ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * to fully opaque, respectively. For non-paletted images, there is a 151ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * single color specified that should be treated as fully transparent. 152ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * Data is valid if (valid & PNG_INFO_tRNS) is non-zero. 153ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 154ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_bytep trans_alpha; /* alpha values for paletted image */ 155ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_color_16 trans_color; /* transparent color for non-palette image */ 156ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 157ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 158ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) 159ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The bKGD chunk gives the suggested image background color if the 160ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * display program does not have its own background color and the image 161ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * is needs to composited onto a background before display. The colors 162ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * in "background" are normally in the same color space/depth as the 163ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero. 164ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 165ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_color_16 background; 166ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 167ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 168ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_oFFs_SUPPORTED 169ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards 170ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * and downwards from the top-left corner of the display, page, or other 171ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * application-specific co-ordinate space. See the PNG_OFFSET_ defines 172ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero. 173ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 174ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_int_32 x_offset; /* x offset on page */ 175ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_int_32 y_offset; /* y offset on page */ 176ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte offset_unit_type; /* offset units type */ 177ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 178ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 179ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_pHYs_SUPPORTED 180ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The pHYs chunk gives the physical pixel density of the image for 181ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_ 182ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero. 183ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 184ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_uint_32 x_pixels_per_unit; /* horizontal pixel density */ 185ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_uint_32 y_pixels_per_unit; /* vertical pixel density */ 186ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */ 187ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 188ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 189ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_hIST_SUPPORTED 190ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The hIST chunk contains the relative frequency or importance of the 191ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * various palette entries, so that a viewer can intelligently select a 192ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * reduced-color palette, if required. Data is an array of "num_palette" 193ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST) 194ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * is non-zero. 195ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 196ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_uint_16p hist; 197ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 198ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 199ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_pCAL_SUPPORTED 200ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The pCAL chunk describes a transformation between the stored pixel 201ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * values and original physical data values used to create the image. 202ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * The integer range [0, 2^bit_depth - 1] maps to the floating-point 203ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * range given by [pcal_X0, pcal_X1], and are further transformed by a 204ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * (possibly non-linear) transformation function given by "pcal_type" 205ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_ 206ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * defines below, and the PNG-Group's PNG extensions document for a 207ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * complete description of the transformations and how they should be 208ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * implemented, and for a description of the ASCII parameter strings. 209ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * Data values are valid if (valid & PNG_INFO_pCAL) non-zero. 210ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 211ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_charp pcal_purpose; /* pCAL chunk description string */ 212ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_int_32 pcal_X0; /* minimum value */ 213ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_int_32 pcal_X1; /* maximum value */ 214ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_charp pcal_units; /* Latin-1 string giving physical units */ 215ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_charpp pcal_params; /* ASCII strings containing parameter values */ 216ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */ 217ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte pcal_nparams; /* number of parameters given in pcal_params */ 218ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 219ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 220ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik/* New members added in libpng-1.0.6 */ 221ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_uint_32 free_me; /* flags items libpng is responsible for freeing */ 222ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 223ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED 224ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* Storage for unknown chunks that the library doesn't recognize. */ 225ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_unknown_chunkp unknown_chunks; 226ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 227ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The type of this field is limited by the type of 228ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * png_struct::user_chunk_cache_max, else overflow can occur. 229ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 230ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik int unknown_chunks_num; 231ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 232ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 233ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_sPLT_SUPPORTED 234ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* Data on sPLT chunks (there may be more than one). */ 235ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_sPLT_tp splt_palettes; 236ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik int splt_palettes_num; /* Match type returned by png_get API */ 237ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 238ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 239ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_sCAL_SUPPORTED 240ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* The sCAL chunk describes the actual physical dimensions of the 241ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * subject matter of the graphic. The chunk contains a unit specification 242ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * a byte value, and two ASCII strings representing floating-point 243ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * values. The values are width and height corresponsing to one pixel 244ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * in the image. Data values are valid if (valid & PNG_INFO_sCAL) is 245ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik * non-zero. 246ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik */ 247ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_byte scal_unit; /* unit of physical scale */ 248ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_charp scal_s_width; /* string containing height */ 249ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_charp scal_s_height; /* string containing width */ 250ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 251ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 252ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#ifdef PNG_INFO_IMAGE_SUPPORTED 253ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) 254ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik non-zero */ 255ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik /* Data valid if (valid & PNG_INFO_IDAT) non-zero */ 256ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik png_bytepp row_pointers; /* the image bits */ 257ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif 258ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik 259ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik}; 260ca2bf81b02c99afa2e76b3b2c6eb232c239221e0Chris Craik#endif /* PNGINFO_H */ 261