Function convert_pixel_format

src/render/quantization.cpp:86–323

}

Image* convert_pixel_format(
  const Image* image,
  Image* new_image,
  PixelFormat pixelFormat,
  DitheringMethod ditheringMethod,
  const RgbMap* rgbmap,
  const Palette* palette,
  bool is_background,
  color_t new_mask_color)
{
  if (!new_image)
    new_image = Image::create(pixelFormat, image->width(), image->height());
  new_image->setMaskColor(new_mask_color);

  // RGB -> Indexed with ordered dithering
  if (image->pixelFormat() == IMAGE_RGB &&
      pixelFormat == IMAGE_INDEXED &&
      ditheringMethod == DitheringMethod::ORDERED) {
    BayerMatrix<8> matrix;
    OrderedDither dither;
    dither.ditherRgbImageToIndexed(matrix, image, new_image, 0, 0, rgbmap, palette);
    return new_image;
  }

  color_t c;
  int r, g, b, a;

  switch (image->pixelFormat()) {

    case IMAGE_RGB: {
      const LockImageBits<RgbTraits> srcBits(image);
      LockImageBits<RgbTraits>::const_iterator src_it = srcBits.begin(), src_end = srcBits.end();

      switch (new_image->pixelFormat()) {

        // RGB -> RGB
        case IMAGE_RGB:
          new_image->copy(image, gfx::Clip(image->bounds()));
          break;

        // RGB -> Grayscale
        case IMAGE_GRAYSCALE: {
          LockImageBits<GrayscaleTraits> dstBits(new_image, Image::WriteLock);
          LockImageBits<GrayscaleTraits>::iterator dst_it = dstBits.begin();
#ifdef _DEBUG
          LockImageBits<GrayscaleTraits>::iterator dst_end = dstBits.end();
#endif

          for (; src_it != src_end; ++src_it, ++dst_it) {
            ASSERT(dst_it != dst_end);
            c = *src_it;

            g = 255 * Hsv(Rgb(rgba_getr(c),
                              rgba_getg(c),
                              rgba_getb(c))).valueInt() / 100;

            *dst_it = graya(g, rgba_geta(c));
          }