Troubleshooting

Bug Reports

You can submit a bug report using GitHub Issues.

Common Problems

Some TIFF images fail to convert (single page)

Problems with TIFF images are normal. The image is either not up to the specification, incompatible or corrupted.

You can fix non-compliant TIFF images with tiffcp. Install libtiff-tools with your package manager. Example: tiffcp input.tif output.tif.

Note

Multipage TIFF images and some compression algorithms are not supported.

Lossless JPEG Transcoding fails on some JPEG images

Enable “Normalize”. This feature is described here. Keep in mind this option alters the checksums in the JPEG images you can reconstruct.

While the vast majority of JPEG images can be losslessly transcoded, there are minor exceptions.

Limitations:

  • No CMYK images.

  • No more than 4 MB of arbitrary tail data is allowed.

  • No unused quantization tables.

  • Possibly more limitations.

Encoding JPEG XL is slow / takes up too much RAM.

Use settings with low RAM consumption.

Settings with minimal RAM usage and fast encoding:

  • Lossy (VarDCT) - Effort 1 - 7.

  • Lossless (Modular) - Effort 1 - 9.

Settings with high RAM usage and slow encoding:

  • Lossy (VarDCT) - Effort 8 - 10.

  • Lossy (Modular).

This program fails to read an image, but my image viewer can open it fine.

Image viewers are a poor metric for verifying image integrity. They will often open slightly corrupted or out of spec images. Problems usually occur during transcoding, where image integrity is crucial.

Setting a network disk as output causes problems.

This application is not designed to use networking storage as an output location. It performs many transformations on images in the output directory.

Image fails to process correctly if it has no extension / an incorrect extension.

This program requires the file extension to match its file type. You can use identify from ImageMagick to check the type of an image.

How can I trobleshoot tricky problems?

Enable logging in the Settings, Advanced category, at the very bottom. This allows you to gain more insight into how the program operates.