#include <jpeglib.h>
Master record for a decompression instance
| jpeg_common_fields |
Fields shared with jpeg_compress_struct
| struct jpeg_source_mgr* src |
Source of compressed data
| JDIMENSION image_width |
nominal image width (from SOF marker)
| JDIMENSION image_height |
nominal image height
| int num_components |
# of color components in JPEG image
| J_COLOR_SPACE jpeg_color_space |
colorspace of JPEG image
| J_COLOR_SPACE out_color_space |
colorspace for output
| unsigned int scale_num |
numerator of fraction by which to scale image
| unsigned int scale_denom |
denominator of fraction by which to scale image
| double output_gamma |
image gamma wanted in output
| boolean buffered_image |
TRUE=multiple output passes
| boolean raw_data_out |
TRUE=downsampled data wanted
| J_DCT_METHOD dct_method |
IDCT algorithm selector
| boolean do_fancy_upsampling |
TRUE=apply fancy upsampling
| boolean do_block_smoothing |
TRUE=apply interblock smoothing
| boolean quantize_colors |
TRUE=colormapped output wanted
| J_DITHER_MODE dither_mode |
type of color dithering to use
| boolean two_pass_quantize |
TRUE=use two-pass color quantization
| int desired_number_of_colors |
max # colors to use in created colormap
| boolean enable_1pass_quant |
enable future use of 1-pass quantizer
| boolean enable_external_quant |
enable future use of external colormap
| boolean enable_2pass_quant |
enable future use of 2-pass quantizer
| JDIMENSION output_width |
scaled image width
| JDIMENSION output_height |
scaled image height
| int out_color_components |
# of color components in out_color_space
| int output_components |
# of color components returned
| int rec_outbuf_height |
min recommended height of scanline buffer
| int actual_number_of_colors |
number of entries in use
| JSAMPARRAY colormap |
The color map as a 2-D pixel array
| JDIMENSION output_scanline |
0 .. output_height-1
| JDIMENSION output_offset |
0 .. output_width*output_height
| int input_scan_number |
Number of SOS markers seen so far
| JDIMENSION input_iMCU_row |
Number of iMCU rows completed
| int output_scan_number |
Nominal scan number being displayed
| JDIMENSION output_iMCU_row |
Number of iMCU rows read
| int(* coef_bits)[DCTSIZE2] |
-1 or current Al value for each coef
| JQUANT_TBL* quant_tbl_ptrs[NUM_QUANT_TBLS] |
ptrs to coefficient quantization tables, or NULL if not defined
| JHUFF_TBL* dc_huff_tbl_ptrs[NUM_HUFF_TBLS] |
ptrs to Huffman coding tables for DC component, or NULL if not defined
| JHUFF_TBL* ac_huff_tbl_ptrs[NUM_HUFF_TBLS] |
ptrs to Huffman coding tables for AC component, or NULL if not defined
| int data_precision |
bits of precision in image data comp_info[i] describes component that appears i'th in SOF
| boolean is_baseline |
TRUE if Baseline SOF0 encountered
| boolean progressive_mode |
TRUE if SOFn specifies progressive mode
| boolean arith_code |
TRUE=arithmetic coding, FALSE=Huffman
| UINT8 arith_dc_L[NUM_ARITH_TBLS] |
L values for DC arith-coding tables
| UINT8 arith_dc_U[NUM_ARITH_TBLS] |
U values for DC arith-coding tables
| UINT8 arith_ac_K[NUM_ARITH_TBLS] |
Kx values for AC arith-coding tables
| unsigned int restart_interval |
MCUs per restart interval, or 0 for no restart
| boolean saw_JFIF_marker |
TRUE iff a JFIF APP0 marker was found
| UINT8 JFIF_major_version |
JFIF version number(major)
| UINT8 JFIF_minor_version |
JFIF version number(minor)
| UINT8 density_unit |
JFIF code for pixel size units
| UINT16 X_density |
Horizontal pixel density
| UINT16 Y_density |
Vertical pixel density
| boolean saw_Adobe_marker |
TRUE iff an Adobe APP14 marker was found
| UINT8 Adobe_transform |
Color transform code from Adobe marker
| J_COLOR_TRANSFORM color_transform |
Color transform identifier derived from LSE marker, otherwise zero
| boolean CCIR601_sampling |
TRUE=first samples are cosited
| jpeg_saved_marker_ptr marker_list |
Head of list of saved markers
| int max_h_samp_factor |
largest h_samp_factor
| int max_v_samp_factor |
largest v_samp_factor
| int min_DCT_h_scaled_size |
smallest DCT_h_scaled_size of any component
| int min_DCT_v_scaled_size |
smallest DCT_v_scaled_size of any component
| JDIMENSION total_iMCU_rows |
# of iMCU rows in image
| JSAMPLE* sample_range_limit |
table for fast range-limiting
| int comps_in_scan |
# of JPEG components in this scan
| jpeg_component_info* cur_comp_info[MAX_COMPS_IN_SCAN] |
*cur_comp_info[i] describes component that appears i'th in SOS
| JDIMENSION MCUs_per_row |
# of MCUs across the image
| JDIMENSION MCU_rows_in_scan |
# of MCU rows in the image
| int blocks_in_MCU |
# of DCT blocks per MCU
| int MCU_membership[D_MAX_BLOCKS_IN_MCU] |
MCU_membership[i] is index in cur_comp_info of component owning i'th block in an MCU
| int Al |
progressive JPEG parameters for scan
| int block_size |
the basic DCT block size: 1..16
| const int* natural_order |
natural-order position array for entropy decode
| int lim_Se |
min( Se, DCTSIZE2-1 ) for entropy decode
| int unread_marker |
This field is shared between entropy decoder and marker parser. It is either zero or the code of a JPEG marker that has been read from the data source, but has not yet been processed.
1.9.4 