How to fix the residual 'image' of the previous frame floating over the new content

[sunlulu427]

The iTerm2 and Sixel inline-image protocols anchor the image to specific cells with no native delete sequence. When the I switch away from the Frames sections, those celles are overwritten with text, but the image stays drawn on top - so I see a residual "image" of the previous frame floating over the new section's content. Force unicode-block rendering for the protocols did resolve the problem, but the resolution is not correct.

• Using the unicode-block image protocol, super low resolution.

• Using the iterm2 image protocol, residual image

• the code

Image.memory(
  _framePngData!,
  width: needsCover ? availableWidth : null,
  height: imgHeight,
  fit: needsCover ? BoxFit.cover : BoxFit.contain,
  protocol: forceUnicodeBlocks ? ImageProtocol.unicodeBlocks : null, // protocol
  placeholder: const Text('Loading...',
      style: TextStyle(color: Colors.gray)),
  errorWidget: const Text('Decode error',
      style: TextStyle(color: Colors.red)),
)