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I'm scanning some old family photos using Image Capture. I want a lossless image using TIFF and LZW compression. What I'm seeing, thanks to the tiffutil -info <file> command, is that the .tiff files that are being outputted are getting a mix of Compression Scheme: Lempel-Ziv & Welch encoding (aka LZW) and Compression Scheme: JPEG encoding.

  1. Does anyone know why Image Capture would switch compression formats? I can't seem to find a pattern as to when it does this but it does seem dependent on the image being scanned.
  2. Is there a way to force it to use LZW, always?
  3. Why would anyone want a lossy compression (JPEG) inside a format (TIFF) generally known for being lossless?

Here are some examples of scanned images. The full TIFFs are available in this Dropbox folder.

1.tiff enter image description here

2.tiff enter image description here

Here is the corresponding tiffutil output:

1.tiff: JPEG compression support is not configured.
Directory at 0x8
  Image Width: 1515 Image Length: 2639
  Resolution: 600, 600
  Resolution Unit: pixels/inch
  Bits/Sample: 8
  Sample Format: unsigned integer
  Compression Scheme: JPEG encoding
  Photometric Interpretation: RGB color
  Alpha: Present
  FillOrder: msb-to-lsb
  Predictor: none
  Software: "Apple Image Capture"
  Model: "Brother HL-L3290CDW series"
  Orientation: row 0 top, col 0 lhs
  Samples/Pixel: 4
  Rows/Strip: 16
  Number of Strips: 165
  Planar Configuration: Not planar
  Profile Name: Scanner RGB Profile

*** 2.tiff
Directory at 0x8
  Image Width: 1520 Image Length: 2641
  Resolution: 600, 600
  Resolution Unit: pixels/inch
  Bits/Sample: 8
  Sample Format: unsigned integer
  Compression Scheme: Lempel-Ziv & Welch encoding
  Photometric Interpretation: RGB color
  Alpha: Present
  FillOrder: msb-to-lsb
  Predictor: horizontal differencing
  Host Computer: "Apple Mac OS X"
  Software: "Apple Image Capture"
  Make: "Brother"
  Model: "HL-L3290CDW series"
  Orientation: row 0 top, col 0 lhs
  Samples/Pixel: 4
  Rows/Strip: 21
  Number of Strips: 126
  Planar Configuration: Not planar
  Profile Name: Generic RGB Profile
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  • Can you give examples of the images? Would be interesting to see if there are any obvious features that would cause the different formats. – compuphys Apr 1 '20 at 13:54
  • @compuphys I've uploaded some samples. Thanks for looking. – spyle Apr 3 '20 at 1:21
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I am encountering this same problem. I realised this when I tried to import my scanned photos into Lightroom and got an error that "The file uses an unsupported compression algorithm".

From some online research and then trying it out myself, it appears that Image Capture for some reason switches compression when the cropping box is at a non-zero angle.

I hope there is a fix for this, but I haven't been able to find any, which is frustrating. I'm now researching other scanning programmes, though the UI of most are not as friendly as Image Capture.

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