Resize Embedded JPEG and Set Maximum File Size
Thank you for developing RawPreviewExtractor. I have been using it to extract the embedded JPEG previews from Canon RAW (CR3) files, and I really like how fast and simple it is.
I would like to suggest adding an option to resize the extracted JPEG and control its file size.
Currently, RawPreviewExtractor extracts the embedded JPEG as-is, at the original preview size. It would be very useful to have the following options:
1. Resize by Long Edge
Add an option such as:
- Original size
- Long edge: 6000 px
- Long edge: 4000 px
- Long edge: 3000 px
- Custom size
For example, if the original embedded JPEG is 6000 × 4000, setting the long edge to 3000 px would produce a 3000 × 2000 JPEG.
2. Maximum JPEG File Size
It would also be very useful to have a maximum file size option, for example:
- No limit
- 5 MB
- 3 MB
- 2 MB
- 1 MB
- Custom size
For example:
Long edge: 3000 px
Maximum file size: 2 MB
The program could automatically adjust JPEG quality/compression to keep each output file below approximately 2 MB.
3. Preserve Embedded JPEG Appearance
The most important point for me is that the extracted JPEG should retain the original camera-generated JPEG appearance, including:
- Picture Style
- White Balance
- Camera color rendering
- Exposure/contrast appearance
I am using Canon EOS R3 CR3 files, and the main reason I use RawPreviewExtractor is that the embedded JPEG already has the camera's JPEG rendering.
LibRaw
Mon, 08/17/2026 - 11:50
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Dear Sir:
Dear Sir:
Our goal is to keep RawPreviewExtractor light, fast, reliable, and focused purely on clean extraction (byte-for-byte extraction of the preview data exactly as the camera wrote it; without any processing / decoding / re-encoding), leaving any downstream modifications completely up to user (ImageMagick?).