// This holds an image as 8bpp RGBA.
struct image_info
{
- image_info() : rows(NULL), hasTransparency(true), is9Patch(false), allocRows(NULL) { }
+ image_info() : rows(NULL), is9Patch(false), allocRows(NULL) { }
~image_info() {
if (rows && rows != allocRows) {
free(rows);
png_uint_32 height;
png_bytepp rows;
- bool hasTransparency;
-
// 9-patch info.
bool is9Patch;
Res_png_9patch info9Patch;
return c;
}
-static void examine_image(image_info* image)
-{
- bool hasTrans = false;
- for (int i=0; i<(int)image->height && !hasTrans; i++) {
- png_bytep p = image->rows[i];
- for (int j=0; j<(int)image->width; j++) {
- if (p[(j*4)+3] != 0xFF) {
- hasTrans = true;
- break;
- }
- }
- }
-
- image->hasTransparency = hasTrans;
-}
-
static status_t do_9patch(const char* imageName, image_info* image)
{
image->is9Patch = true;
return true;
}
+static void dump_image(int w, int h, png_bytepp rows, int bpp)
+{
+ int i, j, rr, gg, bb, aa;
+
+ for (j = 0; j < h; j++) {
+ png_bytep row = rows[j];
+ for (i = 0; i < w; i++) {
+ rr = row[0];
+ gg = row[1];
+ bb = row[2];
+ aa = row[3];
+ row += bpp;
+
+ if (i == 0) {
+ printf("Row %d:", j);
+ }
+ switch (bpp) {
+ case 1:
+ printf(" (%d)", rr);
+ break;
+ case 2:
+ printf(" (%d %d", rr, gg);
+ break;
+ case 3:
+ printf(" (%d %d %d)", rr, gg, bb);
+ break;
+ case 4:
+ printf(" (%d %d %d %d)", rr, gg, bb, aa);
+ break;
+ }
+ if (i == (w - 1)) {
+ NOISY(printf("\n"));
+ }
+ }
+ }
+}
+
+#define MAX(a,b) ((a)>(b)?(a):(b))
+#define ABS(a) ((a)<0?-(a):(a))
+
+static void analyze_image(image_info &imageInfo, int grayscaleTolerance,
+ png_colorp rgbPalette, png_bytep alphaPalette,
+ int *paletteEntries, bool *hasTransparency, int *colorType,
+ png_bytepp outRows)
+{
+ int w = imageInfo.width;
+ int h = imageInfo.height;
+ int i, j, rr, gg, bb, aa, idx;
+ uint32_t colors[256], col;
+ int num_colors = 0;
+ int maxGrayDeviation = 0;
+
+ bool isOpaque = true;
+ bool isPalette = true;
+ bool isGrayscale = true;
+
+ // Scan the entire image and determine if:
+ // 1. Every pixel has R == G == B (grayscale)
+ // 2. Every pixel has A == 255 (opaque)
+ // 3. There are no more than 256 distinct RGBA colors
+
+ // NOISY(printf("Initial image data:\n"));
+ // dump_image(w, h, imageInfo.rows, 4);
+
+ for (j = 0; j < h; j++) {
+ png_bytep row = imageInfo.rows[j];
+ png_bytep out = outRows[j];
+ for (i = 0; i < w; i++) {
+ rr = *row++;
+ gg = *row++;
+ bb = *row++;
+ aa = *row++;
+
+ int odev = maxGrayDeviation;
+ maxGrayDeviation = MAX(ABS(rr - gg), maxGrayDeviation);
+ maxGrayDeviation = MAX(ABS(gg - bb), maxGrayDeviation);
+ maxGrayDeviation = MAX(ABS(bb - rr), maxGrayDeviation);
+ if (maxGrayDeviation > odev) {
+ NOISY(printf("New max dev. = %d at pixel (%d, %d) = (%d %d %d %d)\n",
+ maxGrayDeviation, i, j, rr, gg, bb, aa));
+ }
+
+ // Check if image is really grayscale
+ if (isGrayscale) {
+ if (rr != gg || rr != bb) {
+ NOISY(printf("Found a non-gray pixel at %d, %d = (%d %d %d %d)\n",
+ i, j, rr, gg, bb, aa));
+ isGrayscale = false;
+ }
+ }
+
+ // Check if image is really opaque
+ if (isOpaque) {
+ if (aa != 0xff) {
+ NOISY(printf("Found a non-opaque pixel at %d, %d = (%d %d %d %d)\n",
+ i, j, rr, gg, bb, aa));
+ isOpaque = false;
+ }
+ }
+
+ // Check if image is really <= 256 colors
+ if (isPalette) {
+ col = (uint32_t) ((rr << 24) | (gg << 16) | (bb << 8) | aa);
+ bool match = false;
+ for (idx = 0; idx < num_colors; idx++) {
+ if (colors[idx] == col) {
+ match = true;
+ break;
+ }
+ }
+
+ // Write the palette index for the pixel to outRows optimistically
+ // We might overwrite it later if we decide to encode as gray or
+ // gray + alpha
+ *out++ = idx;
+ if (!match) {
+ if (num_colors == 256) {
+ NOISY(printf("Found 257th color at %d, %d\n", i, j));
+ isPalette = false;
+ } else {
+ colors[num_colors++] = col;
+ }
+ }
+ }
+ }
+ }
+
+ *paletteEntries = 0;
+ *hasTransparency = !isOpaque;
+ int bpp = isOpaque ? 3 : 4;
+ int paletteSize = w * h + bpp * num_colors;
+
+ NOISY(printf("isGrayscale = %s\n", isGrayscale ? "true" : "false"));
+ NOISY(printf("isOpaque = %s\n", isOpaque ? "true" : "false"));
+ NOISY(printf("isPalette = %s\n", isPalette ? "true" : "false"));
+ NOISY(printf("Size w/ palette = %d, gray+alpha = %d, rgb(a) = %d\n",
+ paletteSize, 2 * w * h, bpp * w * h));
+ NOISY(printf("Max gray deviation = %d, tolerance = %d\n", maxGrayDeviation, grayscaleTolerance));
+
+ // Choose the best color type for the image.
+ // 1. Opaque gray - use COLOR_TYPE_GRAY at 1 byte/pixel
+ // 2. Gray + alpha - use COLOR_TYPE_PALETTE if the number of distinct combinations
+ // is sufficiently small, otherwise use COLOR_TYPE_GRAY_ALPHA
+ // 3. RGB(A) - use COLOR_TYPE_PALETTE if the number of distinct colors is sufficiently
+ // small, otherwise use COLOR_TYPE_RGB{_ALPHA}
+ if (isGrayscale) {
+ if (isOpaque) {
+ *colorType = PNG_COLOR_TYPE_GRAY; // 1 byte/pixel
+ } else {
+ // Use a simple heuristic to determine whether using a palette will
+ // save space versus using gray + alpha for each pixel.
+ // This doesn't take into account chunk overhead, filtering, LZ
+ // compression, etc.
+ if (isPalette && (paletteSize < 2 * w * h)) {
+ *colorType = PNG_COLOR_TYPE_PALETTE; // 1 byte/pixel + 4 bytes/color
+ } else {
+ *colorType = PNG_COLOR_TYPE_GRAY_ALPHA; // 2 bytes per pixel
+ }
+ }
+ } else if (isPalette && (paletteSize < bpp * w * h)) {
+ *colorType = PNG_COLOR_TYPE_PALETTE;
+ } else {
+ if (maxGrayDeviation <= grayscaleTolerance) {
+ NOISY(printf("Forcing image to gray (max deviation = %d)\n", maxGrayDeviation));
+ *colorType = isOpaque ? PNG_COLOR_TYPE_GRAY : PNG_COLOR_TYPE_GRAY_ALPHA;
+ } else {
+ *colorType = isOpaque ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA;
+ }
+ }
+
+ // Perform postprocessing of the image or palette data based on the final
+ // color type chosen
+
+ if (*colorType == PNG_COLOR_TYPE_PALETTE) {
+ // Create separate RGB and Alpha palettes and set the number of colors
+ *paletteEntries = num_colors;
+
+ // Create the RGB and alpha palettes
+ for (int idx = 0; idx < num_colors; idx++) {
+ col = colors[idx];
+ rgbPalette[idx].red = (png_byte) ((col >> 24) & 0xff);
+ rgbPalette[idx].green = (png_byte) ((col >> 16) & 0xff);
+ rgbPalette[idx].blue = (png_byte) ((col >> 8) & 0xff);
+ alphaPalette[idx] = (png_byte) (col & 0xff);
+ }
+ } else if (*colorType == PNG_COLOR_TYPE_GRAY || *colorType == PNG_COLOR_TYPE_GRAY_ALPHA) {
+ // If the image is gray or gray + alpha, compact the pixels into outRows
+ for (j = 0; j < h; j++) {
+ png_bytep row = imageInfo.rows[j];
+ png_bytep out = outRows[j];
+ for (i = 0; i < w; i++) {
+ rr = *row++;
+ gg = *row++;
+ bb = *row++;
+ aa = *row++;
+
+ if (isGrayscale) {
+ *out++ = rr;
+ } else {
+ *out++ = (png_byte) (rr * 0.2126f + gg * 0.7152f + bb * 0.0722f);
+ }
+ if (!isOpaque) {
+ *out++ = aa;
+ }
+ }
+ }
+ }
+}
+
+
static void write_png(const char* imageName,
png_structp write_ptr, png_infop write_info,
- image_info& imageInfo)
+ image_info& imageInfo, int grayscaleTolerance)
{
+ bool optimize = true;
png_uint_32 width, height;
int color_type;
int bit_depth, interlace_type, compression_type;
png_unknown_chunk unknowns[1];
+ png_bytepp outRows = (png_bytepp) malloc((int) imageInfo.height * png_sizeof(png_bytep));
+ if (outRows == (png_bytepp) 0) {
+ printf("Can't allocate output buffer!\n");
+ exit(1);
+ }
+ for (i = 0; i < (int) imageInfo.height; i++) {
+ outRows[i] = (png_bytep) malloc(2 * (int) imageInfo.width);
+ if (outRows[i] == (png_bytep) 0) {
+ printf("Can't allocate output buffer!\n");
+ exit(1);
+ }
+ }
+
png_set_compression_level(write_ptr, Z_BEST_COMPRESSION);
- color_type = PNG_COLOR_MASK_COLOR;
- if (imageInfo.hasTransparency) {
- color_type |= PNG_COLOR_MASK_ALPHA;
+ NOISY(printf("Writing image %s: w = %d, h = %d\n", imageName,
+ (int) imageInfo.width, (int) imageInfo.height));
+
+ png_color rgbPalette[256];
+ png_byte alphaPalette[256];
+ bool hasTransparency;
+ int paletteEntries;
+
+ analyze_image(imageInfo, grayscaleTolerance, rgbPalette, alphaPalette,
+ &paletteEntries, &hasTransparency, &color_type, outRows);
+ switch (color_type) {
+ case PNG_COLOR_TYPE_PALETTE:
+ NOISY(printf("Image %s has %d colors%s, using PNG_COLOR_TYPE_PALETTE\n",
+ imageName, paletteEntries,
+ hasTransparency ? " (with alpha)" : ""));
+ break;
+ case PNG_COLOR_TYPE_GRAY:
+ NOISY(printf("Image %s is opaque gray, using PNG_COLOR_TYPE_GRAY\n", imageName));
+ break;
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ NOISY(printf("Image %s is gray + alpha, using PNG_COLOR_TYPE_GRAY_ALPHA\n", imageName));
+ break;
+ case PNG_COLOR_TYPE_RGB:
+ NOISY(printf("Image %s is opaque RGB, using PNG_COLOR_TYPE_RGB\n", imageName));
+ break;
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ NOISY(printf("Image %s is RGB + alpha, using PNG_COLOR_TYPE_RGB_ALPHA\n", imageName));
+ break;
}
png_set_IHDR(write_ptr, write_info, imageInfo.width, imageInfo.height,
8, color_type, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+ if (color_type == PNG_COLOR_TYPE_PALETTE) {
+ png_set_PLTE(write_ptr, write_info, rgbPalette, paletteEntries);
+ if (hasTransparency) {
+ png_set_tRNS(write_ptr, write_info, alphaPalette, paletteEntries, (png_color_16p) 0);
+ }
+ png_set_filter(write_ptr, 0, PNG_NO_FILTERS);
+ } else {
+ png_set_filter(write_ptr, 0, PNG_ALL_FILTERS);
+ }
+
if (imageInfo.is9Patch) {
NOISY(printf("Adding 9-patch info...\n"));
strcpy((char*)unknowns[0].name, "npTc");
png_write_info(write_ptr, write_info);
- if (!imageInfo.hasTransparency) {
+ png_bytepp rows;
+ if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
png_set_filler(write_ptr, 0, PNG_FILLER_AFTER);
+ rows = imageInfo.rows;
+ } else {
+ rows = outRows;
}
-
- png_write_image(write_ptr, imageInfo.rows);
+ png_write_image(write_ptr, rows);
+
+// int bpp;
+// if (color_type == PNG_COLOR_TYPE_PALETTE || color_type == PNG_COLOR_TYPE_GRAY) {
+// bpp = 1;
+// } else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
+// bpp = 2;
+// } else if (color_type == PNG_COLOR_TYPE_RGB) {
+// bpp = 4;
+// } else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
+// bpp = 4;
+// } else {
+// printf("Uknknown color type %d, exiting.\n", color_type);
+// exit(1);
+// }
+// NOISY(printf("Final image data:\n"));
+// dump_image(imageInfo.width, imageInfo.height, rows, bpp);
png_write_end(write_ptr, write_info);
+ for (i = 0; i < (int) imageInfo.height; i++) {
+ free(outRows[i]);
+ }
+ free(outRows);
+
png_get_IHDR(write_ptr, write_info, &width, &height,
&bit_depth, &color_type, &interlace_type,
&compression_type, NULL);
return NO_ERROR;
}
- // Example of renaming a file:
- //*outNewLeafName = file->getPath().getBasePath().getFileName();
- //outNewLeafName->append(".nupng");
+ // Example of renaming a file:
+ //*outNewLeafName = file->getPath().getBasePath().getFileName();
+ //outNewLeafName->append(".nupng");
String8 printableName(file->getPrintableSource());
read_png(printableName.string(), read_ptr, read_info, &imageInfo);
- examine_image(&imageInfo);
-
if (nameLen > 6) {
const char* name = file->getPath().string();
if (name[nameLen-5] == '9' && name[nameLen-6] == '.') {
goto bail;
}
- write_png(printableName.string(), write_ptr, write_info, imageInfo);
+ write_png(printableName.string(), write_ptr, write_info, imageInfo,
+ bundle->getGrayscaleTolerance());
error = NO_ERROR;
projects / android / aapt.git / blobdiff