[BUG] Image quality degradation

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When Claude Code reads image files (PNG, JPG, WebP) using the Read tool, the images are being recompressed/re-encoded. The file size and visual quality change compared to the original file on disk.

Real-world impact: I work with images that get used on a website. When I have Claude Code read/process images as part of my workflow (e.g. reviewing assets, comparing variants, picking final versions), the version Claude sees and operates on is already degraded. By the time the image lands on the web, it has been recompressed at least once by Claude Code on top of any other pipeline compression — resulting in visible quality loss (artifacts around text, banding in gradients, softening of fine detail).

For anyone using Claude Code as part of an asset/content pipeline, this means:

Final web images are lower quality than the source files
Claude is making decisions (which crop, which variant, etc.) based on a degraded preview, not the actual asset
There's no warning or option to opt out

What Should Happen?

The Read tool should pass image bytes through losslessly, OR provide an explicit option to read the original file without re-encoding. If a size cap is necessary for the model context, it should:

Preserve the original file on disk untouched (this may already be true — but worth confirming)
Be transparent: report when an image has been downscaled/recompressed and by how much
Allow a --raw / lossless mode for image-pipeline workflows

Error Messages/Logs

Steps to Reproduce

1. Save a high-quality PNG to disk, e.g. /tmp/source.png — note ls -la /tmp/source.png (file size) and dimensions
2. In Claude Code: read /tmp/source.png
3. Ask Claude to report the dimensions / size of what it received
4. Compare against the original file on disk
5. Observe: size and/or quality differ from the source

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.126

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_