static FIBITMAP * DLL_CALLCONV Load(FreeImageIO *io, fi_handle handle, int page, int flags, void *data) { png_structp png_ptr = NULL; png_infop info_ptr = NULL; png_uint_32 width, height; int color_type; int bit_depth; int pixel_depth = 0; // pixel_depth = bit_depth * channels FIBITMAP *dib = NULL; png_bytepp row_pointers = NULL; fi_ioStructure fio; fio.s_handle = handle; fio.s_io = io; if (handle) { BOOL header_only = (flags & FIF_LOAD_NOPIXELS) == FIF_LOAD_NOPIXELS; try { // check to see if the file is in fact a PNG file BYTE png_check[PNG_BYTES_TO_CHECK]; io->read_proc(png_check, PNG_BYTES_TO_CHECK, 1, handle); if (png_sig_cmp(png_check, (png_size_t)0, PNG_BYTES_TO_CHECK) != 0) { return NULL; // Bad signature } // create the chunk manage structure png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, error_handler, warning_handler); if (!png_ptr) { return NULL; } // create the info structure info_ptr = png_create_info_struct(png_ptr); if (!info_ptr) { png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL); return NULL; } // init the IO png_set_read_fn(png_ptr, &fio, _ReadProc); if (setjmp(png_jmpbuf(png_ptr))) { png_destroy_read_struct(&png_ptr, &info_ptr, NULL); return NULL; } // because we have already read the signature... png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); // read the IHDR chunk png_read_info(png_ptr, info_ptr); png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, NULL, NULL, NULL); // configure the decoder FREE_IMAGE_TYPE image_type = FIT_BITMAP; if(!ConfigureDecoder(png_ptr, info_ptr, flags, &image_type)) { throw FI_MSG_ERROR_UNSUPPORTED_FORMAT; } // update image info color_type = png_get_color_type(png_ptr, info_ptr); bit_depth = png_get_bit_depth(png_ptr, info_ptr); pixel_depth = bit_depth * png_get_channels(png_ptr, info_ptr); // create a dib and write the bitmap header // set up the dib palette, if needed switch (color_type) { case PNG_COLOR_TYPE_RGB: case PNG_COLOR_TYPE_RGB_ALPHA: dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, pixel_depth, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK); break; case PNG_COLOR_TYPE_PALETTE: dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, pixel_depth, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK); if(dib) { png_colorp png_palette = NULL; int palette_entries = 0; png_get_PLTE(png_ptr,info_ptr, &png_palette, &palette_entries); palette_entries = MIN((unsigned)palette_entries, FreeImage_GetColorsUsed(dib)); // store the palette RGBQUAD *palette = FreeImage_GetPalette(dib); for(int i = 0; i < palette_entries; i++) { palette[i].rgbRed = png_palette[i].red; palette[i].rgbGreen = png_palette[i].green; palette[i].rgbBlue = png_palette[i].blue; } } break; case PNG_COLOR_TYPE_GRAY: dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, pixel_depth, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK); if(dib && (pixel_depth <= 8)) { RGBQUAD *palette = FreeImage_GetPalette(dib); const int palette_entries = 1 << pixel_depth; for(int i = 0; i < palette_entries; i++) { palette[i].rgbRed = palette[i].rgbGreen = palette[i].rgbBlue = (BYTE)((i * 255) / (palette_entries - 1)); } } break; default: throw FI_MSG_ERROR_UNSUPPORTED_FORMAT; } if(!dib) { throw FI_MSG_ERROR_DIB_MEMORY; } // store the transparency table if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) { // array of alpha (transparency) entries for palette png_bytep trans_alpha = NULL; // number of transparent entries int num_trans = 0; // graylevel or color sample values of the single transparent color for non-paletted images png_color_16p trans_color = NULL; png_get_tRNS(png_ptr, info_ptr, &trans_alpha, &num_trans, &trans_color); if((color_type == PNG_COLOR_TYPE_GRAY) && trans_color) { // single transparent color if (trans_color->gray < 256) { BYTE table[256]; memset(table, 0xFF, 256); table[trans_color->gray] = 0; FreeImage_SetTransparencyTable(dib, table, 256); } // check for a full transparency table, too else if ((trans_alpha) && (pixel_depth <= 8)) { FreeImage_SetTransparencyTable(dib, (BYTE *)trans_alpha, num_trans); } } else if((color_type == PNG_COLOR_TYPE_PALETTE) && trans_alpha) { // transparency table FreeImage_SetTransparencyTable(dib, (BYTE *)trans_alpha, num_trans); } } // store the background color (only supported for FIT_BITMAP types) if ((image_type == FIT_BITMAP) && png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD)) { // Get the background color to draw transparent and alpha images over. // Note that even if the PNG file supplies a background, you are not required to // use it - you should use the (solid) application background if it has one. png_color_16p image_background = NULL; RGBQUAD rgbBkColor; if (png_get_bKGD(png_ptr, info_ptr, &image_background)) { rgbBkColor.rgbRed = (BYTE)image_background->red; rgbBkColor.rgbGreen = (BYTE)image_background->green; rgbBkColor.rgbBlue = (BYTE)image_background->blue; rgbBkColor.rgbReserved = 0; FreeImage_SetBackgroundColor(dib, &rgbBkColor); } } // get physical resolution if (png_get_valid(png_ptr, info_ptr, PNG_INFO_pHYs)) { png_uint_32 res_x, res_y; // we'll overload this var and use 0 to mean no phys data, // since if it's not in meters we can't use it anyway int res_unit_type = PNG_RESOLUTION_UNKNOWN; png_get_pHYs(png_ptr,info_ptr, &res_x, &res_y, &res_unit_type); if (res_unit_type == PNG_RESOLUTION_METER) { FreeImage_SetDotsPerMeterX(dib, res_x); FreeImage_SetDotsPerMeterY(dib, res_y); } } // get possible ICC profile if (png_get_valid(png_ptr, info_ptr, PNG_INFO_iCCP)) { png_charp profile_name = NULL; png_bytep profile_data = NULL; png_uint_32 profile_length = 0; int compression_type; png_get_iCCP(png_ptr, info_ptr, &profile_name, &compression_type, &profile_data, &profile_length); // copy ICC profile data (must be done after FreeImage_AllocateHeader) FreeImage_CreateICCProfile(dib, profile_data, profile_length); } // --- header only mode => clean-up and return if (header_only) { // get possible metadata (it can be located both before and after the image data) ReadMetadata(png_ptr, info_ptr, dib); if (png_ptr) { // clean up after the read, and free any memory allocated - REQUIRED png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL); } return dib; } // set the individual row_pointers to point at the correct offsets row_pointers = (png_bytepp)malloc(height * sizeof(png_bytep)); if (!row_pointers) { png_destroy_read_struct(&png_ptr, &info_ptr, NULL); FreeImage_Unload(dib); return NULL; } // read in the bitmap bits via the pointer table // allow loading of PNG with minor errors (such as images with several IDAT chunks) for (png_uint_32 k = 0; k < height; k++) { row_pointers[height - 1 - k] = FreeImage_GetScanLine(dib, k); } png_set_benign_errors(png_ptr, 1); png_read_image(png_ptr, row_pointers); // check if the bitmap contains transparency, if so enable it in the header if (FreeImage_GetBPP(dib) == 32) { if (FreeImage_GetColorType(dib) == FIC_RGBALPHA) { FreeImage_SetTransparent(dib, TRUE); } else { FreeImage_SetTransparent(dib, FALSE); } } // cleanup if (row_pointers) { free(row_pointers); row_pointers = NULL; } // read the rest of the file, getting any additional chunks in info_ptr png_read_end(png_ptr, info_ptr); // get possible metadata (it can be located both before and after the image data) ReadMetadata(png_ptr, info_ptr, dib); if (png_ptr) { // clean up after the read, and free any memory allocated - REQUIRED png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL); } return dib; } catch (const char *text) { if (png_ptr) { png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL); } if (row_pointers) { free(row_pointers); } if (dib) { FreeImage_Unload(dib); } FreeImage_OutputMessageProc(s_format_id, text); return NULL; } } return NULL; }
static FIBITMAP * DLL_CALLCONV Load(FreeImageIO *io, fi_handle handle, int page, int flags, void *data) { png_structp png_ptr = NULL; png_infop info_ptr; png_uint_32 width, height; png_colorp png_palette = NULL; int color_type, palette_entries = 0; int bit_depth, pixel_depth; // pixel_depth = bit_depth * channels FIBITMAP *dib = NULL; RGBQUAD *palette = NULL; // pointer to dib palette png_bytepp row_pointers = NULL; int i; fi_ioStructure fio; fio.s_handle = handle; fio.s_io = io; if (handle) { BOOL header_only = (flags & FIF_LOAD_NOPIXELS) == FIF_LOAD_NOPIXELS; try { // check to see if the file is in fact a PNG file BYTE png_check[PNG_BYTES_TO_CHECK]; io->read_proc(png_check, PNG_BYTES_TO_CHECK, 1, handle); if (png_sig_cmp(png_check, (png_size_t)0, PNG_BYTES_TO_CHECK) != 0) { return NULL; // Bad signature } // create the chunk manage structure png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, error_handler, warning_handler); if (!png_ptr) { return NULL; } // create the info structure info_ptr = png_create_info_struct(png_ptr); if (!info_ptr) { png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL); return NULL; } // init the IO png_set_read_fn(png_ptr, &fio, _ReadProc); if (setjmp(png_jmpbuf(png_ptr))) { png_destroy_read_struct(&png_ptr, &info_ptr, NULL); return NULL; } // because we have already read the signature... png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); // read the IHDR chunk png_read_info(png_ptr, info_ptr); png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, NULL, NULL, NULL); pixel_depth = png_get_bit_depth(png_ptr, info_ptr) * png_get_channels(png_ptr, info_ptr); // get image data type (assume standard image type) FREE_IMAGE_TYPE image_type = FIT_BITMAP; if (bit_depth == 16) { if ((pixel_depth == 16) && (color_type == PNG_COLOR_TYPE_GRAY)) { image_type = FIT_UINT16; } else if ((pixel_depth == 48) && (color_type == PNG_COLOR_TYPE_RGB)) { image_type = FIT_RGB16; } else if ((pixel_depth == 64) && (color_type == PNG_COLOR_TYPE_RGB_ALPHA)) { image_type = FIT_RGBA16; } else { // tell libpng to strip 16 bit/color files down to 8 bits/color png_set_strip_16(png_ptr); bit_depth = 8; } } #ifndef FREEIMAGE_BIGENDIAN if((image_type == FIT_UINT16) || (image_type == FIT_RGB16) || (image_type == FIT_RGBA16)) { // turn on 16 bit byte swapping png_set_swap(png_ptr); } #endif // set some additional flags switch(color_type) { case PNG_COLOR_TYPE_RGB: case PNG_COLOR_TYPE_RGB_ALPHA: #if FREEIMAGE_COLORORDER == FREEIMAGE_COLORORDER_BGR // flip the RGB pixels to BGR (or RGBA to BGRA) if(image_type == FIT_BITMAP) { png_set_bgr(png_ptr); } #endif break; case PNG_COLOR_TYPE_PALETTE: // expand palette images to the full 8 bits from 2 bits/pixel if (pixel_depth == 2) { png_set_packing(png_ptr); pixel_depth = 8; } break; case PNG_COLOR_TYPE_GRAY: // expand grayscale images to the full 8 bits from 2 bits/pixel // but *do not* expand fully transparent palette entries to a full alpha channel if (pixel_depth == 2) { png_set_expand_gray_1_2_4_to_8(png_ptr); pixel_depth = 8; } break; case PNG_COLOR_TYPE_GRAY_ALPHA: // expand 8-bit greyscale + 8-bit alpha to 32-bit png_set_gray_to_rgb(png_ptr); #if FREEIMAGE_COLORORDER == FREEIMAGE_COLORORDER_BGR // flip the RGBA pixels to BGRA png_set_bgr(png_ptr); #endif pixel_depth = 32; break; default: throw FI_MSG_ERROR_UNSUPPORTED_FORMAT; } // unlike the example in the libpng documentation, we have *no* idea where // this file may have come from--so if it doesn't have a file gamma, don't // do any correction ("do no harm") if (png_get_valid(png_ptr, info_ptr, PNG_INFO_gAMA)) { double gamma = 0; double screen_gamma = 2.2; if (png_get_gAMA(png_ptr, info_ptr, &gamma) && ( flags & PNG_IGNOREGAMMA ) != PNG_IGNOREGAMMA) { png_set_gamma(png_ptr, screen_gamma, gamma); } } // all transformations have been registered; now update info_ptr data png_read_update_info(png_ptr, info_ptr); // color type may have changed, due to our transformations color_type = png_get_color_type(png_ptr,info_ptr); // create a DIB and write the bitmap header // set up the DIB palette, if needed switch (color_type) { case PNG_COLOR_TYPE_RGB: png_set_invert_alpha(png_ptr); if(image_type == FIT_BITMAP) { dib = FreeImage_AllocateHeader(header_only, width, height, 24, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK); } else { dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, pixel_depth); } break; case PNG_COLOR_TYPE_RGB_ALPHA: if(image_type == FIT_BITMAP) { dib = FreeImage_AllocateHeader(header_only, width, height, 32, FI_RGBA_RED_MASK, FI_RGBA_GREEN_MASK, FI_RGBA_BLUE_MASK); } else { dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, pixel_depth); } break; case PNG_COLOR_TYPE_PALETTE: dib = FreeImage_AllocateHeader(header_only, width, height, pixel_depth); png_get_PLTE(png_ptr,info_ptr, &png_palette, &palette_entries); palette_entries = MIN((unsigned)palette_entries, FreeImage_GetColorsUsed(dib)); palette = FreeImage_GetPalette(dib); // store the palette for (i = 0; i < palette_entries; i++) { palette[i].rgbRed = png_palette[i].red; palette[i].rgbGreen = png_palette[i].green; palette[i].rgbBlue = png_palette[i].blue; } break; case PNG_COLOR_TYPE_GRAY: dib = FreeImage_AllocateHeaderT(header_only, image_type, width, height, pixel_depth); if(pixel_depth <= 8) { palette = FreeImage_GetPalette(dib); palette_entries = 1 << pixel_depth; for (i = 0; i < palette_entries; i++) { palette[i].rgbRed = palette[i].rgbGreen = palette[i].rgbBlue = (BYTE)((i * 255) / (palette_entries - 1)); } } break; default: throw FI_MSG_ERROR_UNSUPPORTED_FORMAT; } // store the transparency table if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) { // array of alpha (transparency) entries for palette png_bytep trans_alpha = NULL; // number of transparent entries int num_trans = 0; // graylevel or color sample values of the single transparent color for non-paletted images png_color_16p trans_color = NULL; png_get_tRNS(png_ptr, info_ptr, &trans_alpha, &num_trans, &trans_color); if((color_type == PNG_COLOR_TYPE_GRAY) && trans_color) { // single transparent color if (trans_color->gray < palette_entries) { BYTE table[256]; memset(table, 0xFF, palette_entries); table[trans_color->gray] = 0; FreeImage_SetTransparencyTable(dib, table, palette_entries); } } else if((color_type == PNG_COLOR_TYPE_PALETTE) && trans_alpha) { // transparency table FreeImage_SetTransparencyTable(dib, (BYTE *)trans_alpha, num_trans); } } // store the background color if (png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD)) { // Get the background color to draw transparent and alpha images over. // Note that even if the PNG file supplies a background, you are not required to // use it - you should use the (solid) application background if it has one. png_color_16p image_background = NULL; RGBQUAD rgbBkColor; if (png_get_bKGD(png_ptr, info_ptr, &image_background)) { rgbBkColor.rgbRed = (BYTE)image_background->red; rgbBkColor.rgbGreen = (BYTE)image_background->green; rgbBkColor.rgbBlue = (BYTE)image_background->blue; rgbBkColor.rgbReserved = 0; FreeImage_SetBackgroundColor(dib, &rgbBkColor); } } // get physical resolution if (png_get_valid(png_ptr, info_ptr, PNG_INFO_pHYs)) { png_uint_32 res_x, res_y; // we'll overload this var and use 0 to mean no phys data, // since if it's not in meters we can't use it anyway int res_unit_type = PNG_RESOLUTION_UNKNOWN; png_get_pHYs(png_ptr,info_ptr, &res_x, &res_y, &res_unit_type); if (res_unit_type == PNG_RESOLUTION_METER) { FreeImage_SetDotsPerMeterX(dib, res_x); FreeImage_SetDotsPerMeterY(dib, res_y); } } // get possible ICC profile if (png_get_valid(png_ptr, info_ptr, PNG_INFO_iCCP)) { png_charp profile_name = NULL; png_bytep profile_data = NULL; png_uint_32 profile_length = 0; int compression_type; png_get_iCCP(png_ptr, info_ptr, &profile_name, &compression_type, &profile_data, &profile_length); // copy ICC profile data (must be done after FreeImage_AllocateHeader) FreeImage_CreateICCProfile(dib, profile_data, profile_length); } // --- header only mode => clean-up and return if (header_only) { // get possible metadata (it can be located both before and after the image data) ReadMetadata(png_ptr, info_ptr, dib); if (png_ptr) { // clean up after the read, and free any memory allocated - REQUIRED png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL); } return dib; } // set the individual row_pointers to point at the correct offsets row_pointers = (png_bytepp)malloc(height * sizeof(png_bytep)); if (!row_pointers) { png_destroy_read_struct(&png_ptr, &info_ptr, NULL); FreeImage_Unload(dib); return NULL; } // read in the bitmap bits via the pointer table // allow loading of PNG with minor errors (such as images with several IDAT chunks) for (png_uint_32 k = 0; k < height; k++) { row_pointers[height - 1 - k] = FreeImage_GetScanLine(dib, k); } png_set_benign_errors(png_ptr, 1); png_read_image(png_ptr, row_pointers); // check if the bitmap contains transparency, if so enable it in the header if (FreeImage_GetBPP(dib) == 32) { if (FreeImage_GetColorType(dib) == FIC_RGBALPHA) { FreeImage_SetTransparent(dib, TRUE); } else { FreeImage_SetTransparent(dib, FALSE); } } // cleanup if (row_pointers) { free(row_pointers); row_pointers = NULL; } // read the rest of the file, getting any additional chunks in info_ptr png_read_end(png_ptr, info_ptr); // get possible metadata (it can be located both before and after the image data) ReadMetadata(png_ptr, info_ptr, dib); if (png_ptr) { // clean up after the read, and free any memory allocated - REQUIRED png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL); } return dib; } catch (const char *text) { if (png_ptr) { png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL); } if (row_pointers) { free(row_pointers); } if (dib) { FreeImage_Unload(dib); } FreeImage_OutputMessageProc(s_format_id, text); return NULL; } } return NULL; }
static int /* 0 on success, else an error code */ write_png(const char **name, FILE *fp, int color_type, int bit_depth, volatile png_fixed_point gamma, unsigned int filters, unsigned int *colors) { png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, name, makepng_error, makepng_warning); volatile png_infop info_ptr = NULL; volatile png_bytep row = NULL; if (png_ptr == NULL) { fprintf(stderr, "makepng: OOM allocating write structure\n"); return 1; } if (setjmp(png_jmpbuf(png_ptr))) { png_structp nv_ptr = png_ptr; png_infop nv_info = info_ptr; png_ptr = NULL; info_ptr = NULL; png_destroy_write_struct(&nv_ptr, &nv_info); if (row != NULL) free(row); return 1; } /* Allow benign errors so that we can write PNGs with errors */ png_set_benign_errors(png_ptr, 1/*allowed*/); png_init_io(png_ptr, fp); info_ptr = png_create_info_struct(png_ptr); if (info_ptr == NULL) png_error(png_ptr, "OOM allocating info structure"); unsigned int size = 500; unsigned int i; png_set_IHDR(png_ptr, info_ptr, size, size, bit_depth, color_type, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); if (gamma == PNG_DEFAULT_sRGB) png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_ABSOLUTE); /* Write the file header. */ png_write_info(png_ptr, info_ptr); /* Restrict the filters */ png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, filters); int passes = png_set_interlace_handling(png_ptr); int pass; png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr); row = malloc(rowbytes); if (row == NULL) png_error(png_ptr, "OOM allocating row buffer"); for (pass = 0; pass < passes; ++pass) { unsigned int y; for (y=0; y<size; ++y) { generate_row(row, rowbytes, y, color_type, bit_depth); png_write_row(png_ptr, row); } } /* Finish writing the file. */ png_write_end(png_ptr, info_ptr); png_structp nv_ptr = png_ptr; png_infop nv_info = info_ptr; png_ptr = NULL; info_ptr = NULL; png_destroy_write_struct(&nv_ptr, &nv_info); free(row); return 0; }