Lightroom: Fails to import some valid scanned TIFFs created by Mac Image Capture

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  • Problem
  • Updated 4 months ago
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When LR tries to import some scanned TIFFs created by Mac Image Capture, the import fails with "The file uses an unsupported compression algorithm".  The problem is that LR doesn't implement the representation used by Image Capture with these TIFFs: JPEG compression, 4 samples per pixel (RGB + Alpha), and PhotometricInterpretation = RGB.

For some reason, Image Capture uses this representation on crops with non-zero angles, such as those created by the very useful feature Auto Selection: Detect Separate Items, which identifies and separates multiple photos being scanned.

Here's such a TIFF:

Many programs correctly read this TIFF: Preview (Mac), Gimp (Mac), Photos (Mac), Safari (Mac), Photos (Windows 10), Paint (Windows 10).

Unfortunately, there's a longstanding bug in Photoshop that incorrectly reads this representation:

There are (at least) two workarounds:

1. In Image Capture, save the scans with non-zero angles as JPEGs rather than TIFFs.  These TIFFs use JPEG compression anyway, so there is no advantage to using TIFF over JPEG.

2. Open the TIFF in another program and save it with a different compression algorithm (e.g. none or LZW). 

Unfortunately, you can't use Preview to export as a TIFF, since it seems to have a bug in its Export / Save that ignores the setting Compression = None.  But since the TIFF is already using JPEG compression, simply use Preview to export it as a JPEG, and in this case you won't suffer any additional loss in quality.

Tested with LR 7.4 / Macos 10.13.5. But this problem has been in LR for years, based on reports in the forums.
Photo of John R. Ellis

John R. Ellis, Champion

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Posted 4 months ago

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Simon Chen, Principal Computer Scientist

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Thanks John for the bug report!