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); }