Merge pull request #1640 from fintelia/optimize-bmp-rgba

Optimize decoding of certain RGBA BMP files
image-rs · Dec 20, 2021 · 6301dc6 · 6301dc6
2 parents 5893be0 + 32cdd72
commit 6301dc6
Showing 1 changed file with 9 additions and 0 deletions.
diff --git a/src/codecs/bmp/decoder.rs b/src/codecs/bmp/decoder.rs
@@ -48,6 +48,12 @@ const R8_G8_B8_COLOR_MASK: Bitfields = Bitfields {
  b: Bitfield { len: 8, shift: 8 },
  a: Bitfield { len: 0, shift: 0 },
 };
+const R8_G8_B8_A8_COLOR_MASK: Bitfields = Bitfields {
+ r: Bitfield { len: 8, shift: 16 },
+ g: Bitfield { len: 8, shift: 8 },
+ b: Bitfield { len: 8, shift: 0 },
+ a: Bitfield { len: 8, shift: 24 },
+};
 
 const RLE_ESCAPE: u8 = 0;
 const RLE_ESCAPE_EOL: u8 = 0;
@@ -1460,6 +1466,9 @@ impl<R: Read + Seek> BmpDecoder<R> {
  Some(R8_G8_B8_COLOR_MASK) => {
  self.read_full_byte_pixel_data(&FormatFullBytes::Format888)
  }
+ Some(R8_G8_B8_A8_COLOR_MASK) => {
+ self.read_full_byte_pixel_data(&FormatFullBytes::RGBA32)
+ }
  Some(_) => self.read_32_bit_pixel_data(),
  None => Err(DecoderError::BitfieldMasksMissing(32).into()),
  },