static FIBITMAP * DLL_CALLCONV
Load(FreeImageIO *io, fi_handle handle, int page, int flags, void *data) {
if (handle) {
FIBITMAP *dib = NULL;
try {
// set up the jpeglib structures
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
// step 1: allocate and initialize JPEG decompression object
cinfo.err = jpeg_std_error(&jerr);
jerr.error_exit = jpeg_error_exit;
jerr.output_message = jpeg_output_message;
jpeg_create_decompress(&cinfo);
// step 2a: specify data source (eg, a handle)
jpeg_freeimage_src(&cinfo, handle, io);
// step 2b: save special markers for later reading
jpeg_save_markers(&cinfo, JPEG_COM, 0xFFFF);
for(int m = 0; m < 16; m++) {
jpeg_save_markers(&cinfo, JPEG_APP0 + m, 0xFFFF);
}
// step 3: read handle parameters with jpeg_read_header()
jpeg_read_header(&cinfo, TRUE);
// step 4: set parameters for decompression
unsigned int scale_denom = 1; // fraction by which to scale image
int requested_size = flags >> 16; // requested user size in pixels
if(requested_size > 0) {
// the JPEG codec can perform x2, x4 or x8 scaling on loading
// try to find the more appropriate scaling according to user's need
double scale = MAX((double)cinfo.image_width, (double)cinfo.image_height) / (double)requested_size;
if(scale >= 8) {
scale_denom = 8;
} else if(scale >= 4) {
scale_denom = 4;
} else if(scale >= 2) {
scale_denom = 2;
}
}
cinfo.scale_num = 1;
cinfo.scale_denom = scale_denom;
if ((flags & JPEG_ACCURATE) != JPEG_ACCURATE) {
cinfo.dct_method = JDCT_IFAST;
cinfo.do_fancy_upsampling = FALSE;
}
// step 5a: start decompressor and calculate output width and height
jpeg_start_decompress(&cinfo);
// step 5b: allocate dib and init header
if((cinfo.num_components == 4) && (cinfo.out_color_space == JCS_CMYK)) {
// CMYK image
if((flags & JPEG_CMYK) == JPEG_CMYK) {
// load as CMYK
dib = FreeImage_Allocate(cinfo.output_width, cinfo.output_height, 32, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);
if(!dib) return NULL;
FreeImage_GetICCProfile(dib)->flags |= FIICC_COLOR_IS_CMYK;
} else {
// load as CMYK and convert to RGB
dib = FreeImage_Allocate(cinfo.output_width, cinfo.output_height, 24, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);
if(!dib) return NULL;
}
} else {
// RGB or greyscale image
dib = FreeImage_Allocate(cinfo.output_width, cinfo.output_height, 8 * cinfo.num_components, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK);
if(!dib) return NULL;
if (cinfo.num_components == 1) {
// build a greyscale palette
RGBQUAD *colors = FreeImage_GetPalette(dib);
for (int i = 0; i < 256; i++) {
colors[i].rgbRed = (BYTE)i;
colors[i].rgbGreen = (BYTE)i;
colors[i].rgbBlue = (BYTE)i;
}
}
}
if(scale_denom != 1) {
// store original size info if a scaling was requested
store_size_info(dib, cinfo.image_width, cinfo.image_height);
}
// step 5c: handle metrices
if (cinfo.density_unit == 1) {
// dots/inch
FreeImage_SetDotsPerMeterX(dib, (unsigned) (((float)cinfo.X_density) / 0.0254000 + 0.5));
FreeImage_SetDotsPerMeterY(dib, (unsigned) (((float)cinfo.Y_density) / 0.0254000 + 0.5));
} else if (cinfo.density_unit == 2) {
// dots/cm
FreeImage_SetDotsPerMeterX(dib, (unsigned) (cinfo.X_density * 100));
FreeImage_SetDotsPerMeterY(dib, (unsigned) (cinfo.Y_density * 100));
}
// step 6a: while (scan lines remain to be read) jpeg_read_scanlines(...);
if((cinfo.out_color_space == JCS_CMYK) && ((flags & JPEG_CMYK) != JPEG_CMYK)) {
// convert from CMYK to RGB
JSAMPARRAY buffer; // output row buffer
unsigned row_stride; // physical row width in output buffer
// JSAMPLEs per row in output buffer
row_stride = cinfo.output_width * cinfo.output_components;
// make a one-row-high sample array that will go away when done with image
buffer = (*cinfo.mem->alloc_sarray)((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
while (cinfo.output_scanline < cinfo.output_height) {
JSAMPROW src = buffer[0];
JSAMPROW dst = FreeImage_GetScanLine(dib, cinfo.output_height - cinfo.output_scanline - 1);
jpeg_read_scanlines(&cinfo, buffer, 1);
for(unsigned x = 0; x < FreeImage_GetWidth(dib); x++) {
WORD K = (WORD)src[3];
dst[FI_RGBA_RED] = (BYTE)((K * src[0]) / 255);
dst[FI_RGBA_GREEN] = (BYTE)((K * src[1]) / 255);
dst[FI_RGBA_BLUE] = (BYTE)((K * src[2]) / 255);
src += 4;
dst += 3;
}
}
} else {
// normal case (RGB or greyscale image)
while (cinfo.output_scanline < cinfo.output_height) {
JSAMPROW dst = FreeImage_GetScanLine(dib, cinfo.output_height - cinfo.output_scanline - 1);
jpeg_read_scanlines(&cinfo, &dst, 1);
}
// step 6b: swap red and blue components (see LibJPEG/jmorecfg.h: #define RGB_RED, ...)
// The default behavior of the JPEG library is kept "as is" because LibTIFF uses
// LibJPEG "as is".
#if FREEIMAGE_COLORORDER == FREEIMAGE_COLORORDER_BGR
if(cinfo.num_components == 3) {
for(unsigned y = 0; y < FreeImage_GetHeight(dib); y++) {
BYTE *target = FreeImage_GetScanLine(dib, y);
for(unsigned x = 0; x < FreeImage_GetWidth(dib); x++) {
INPLACESWAP(target[0], target[2]);
target += 3;
}
}
}
#endif
}
// step 7: read special markers
read_markers(&cinfo, dib);
// step 8: finish decompression
jpeg_finish_decompress(&cinfo);
// step 9: release JPEG decompression object
jpeg_destroy_decompress(&cinfo);
// check for automatic Exif rotation
if((flags & JPEG_EXIFROTATE) == JPEG_EXIFROTATE) {
rotate_exif(&dib);
}
// everything went well. return the loaded dib
return (FIBITMAP *)dib;
} catch (...) {
if(NULL != dib) {
FreeImage_Unload(dib);
}
}
}
return NULL;
}
void
jpeg_read (unsigned char *read_buf)
{
//FILE* input;
//FILE* output;
// input = fopen("input.txt", "w");
// output = fopen("output.txt", "w");
/*
* Read markers
*/
read_markers (read_buf);
/*
* Initialize the information used for decoding
*/
jpeg_init_decompress ();
int m,n;
int a;
m=4000;
n= 4000;
//data_to(buff,m);
int i;
//for (i=0;i<4000;i++)
// fprintf(input,"%d\n",buff[i]);
/*
* Start decoding
*/
a = decode_start (
&OutData_image_width,
&OutData_image_height,
OutData_comp_vpos,
OutData_comp_hpos,
OutData_comp_buf,
p_jinfo_image_height,
p_jinfo_image_width,
p_jinfo_smp_fact,
p_jinfo_comps_info_quant_tbl_no,
p_jinfo_comps_info_dc_tbl_no,
p_jinfo_quant_tbl_quantval,
p_jinfo_dc_xhuff_tbl_huffval,
p_jinfo_ac_xhuff_tbl_huffval,
p_jinfo_dc_dhuff_tbl_ml,
p_jinfo_dc_dhuff_tbl_maxcode,
p_jinfo_dc_dhuff_tbl_mincode,
p_jinfo_dc_dhuff_tbl_valptr,
p_jinfo_ac_dhuff_tbl_ml,
p_jinfo_ac_dhuff_tbl_maxcode,
p_jinfo_ac_dhuff_tbl_mincode,
p_jinfo_ac_dhuff_tbl_valptr,
p_jinfo_MCUWidth,
p_jinfo_NumMCU,
p_jinfo_jpeg_data);
// for (i=0;i<4000;i++)
// fprintf(output,"%d\n",buff[i]);
//data_from(buff,n);
//fclose(input);
//fclose(output);
}
