docs: private void readLSD() {
          // Logical screen size.
          header.width = readShort();
          header.height = readShort();
          // Packed fields
          int packed = read();
          // 1 : global color table flag.
          header.gctFlag = (packed & 0x80) != 0;
          // 2-4 : color resolution.
          // 5 : gct sort flag.
          // 6-8 : gct size.
          header.gctSize = 2 << (packed & 7);
          // Background color index.
          header.bgIndex = read();
          // Pixel aspect ratio
          header.pixelAspect = read();
      }