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Wronr reading of 16 bit tiff

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Wronr reading of 16 bit tiff AndyJP 14 Aug 05:04
  Wronr reading of 16 bit tiff Tobias Jakobs via gimp-user-list 14 Aug 06:56
  Wronr reading of 16 bit tiff Liam R E Quin 14 Aug 16:37
   Wronr reading of 16 bit tiff AndyJP 15 Aug 03:14
2019-08-14 05:04:37 UTC (2 months ago)
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Wronr reading of 16 bit tiff

I try scanning to 48bit (16 bit per channel) TIFF with VueScan, but GIMP reads it wrong, forwarding the data partially to alpha-channel. Probably, it is interpreting 3-channel/16bit image as 4-channel/12bit encoded. If not, I have no Idea where that 4-th alpha channel comes from (it is not blank, but filled with some ghost from original image). So probably other channels are also damaged.

There are also error messages appear: "Incompatible type for 'RichTIFFIPTC'; tag ignored" and
"Alpha channel type not defined for file C:\...\.tiff. Assuming alpha is not premultiplied."

Is there a way to read 3-channel 48-bit TIFFs to GIMP correctly?

AndyJP (via www.gimpusers.com/forums)
Tobias Jakobs via gimp-user-list
2019-08-14 06:56:46 UTC (2 months ago)

Wronr reading of 16 bit tiff

Hi Andy,

please open an issue in the Gimp issue tracker and attach an example file: https://gitlab.gnome.org/GNOME/gimp/issues

Some scanners create 4-channel/12bit encodedimages. Then the 4th channel is an IR channel that is useful for reducing dust.

Regards, Tobias

Am Mi., 14. Aug. 2019 um 07:04 Uhr schrieb AndyJP :

I try scanning to 48bit (16 bit per channel) TIFF with VueScan, but GIMP reads
it wrong, forwarding the data partially to alpha-channel. Probably, it is interpreting 3-channel/16bit image as 4-channel/12bit encoded. If not, I have no Idea where that 4-th alpha channel comes from (it is not blank, but filled with some ghost from original image). So probably other channels are also damaged.

There are also error messages appear: "Incompatible type for 'RichTIFFIPTC'; tag ignored" and
"Alpha channel type not defined for file C:\...\.tiff. Assuming alpha is not
premultiplied."

Is there a way to read 3-channel 48-bit TIFFs to GIMP correctly?

-- AndyJP (via www.gimpusers.com/forums) _______________________________________________ gimp-user-list mailing list
List address: gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list

Liam R E Quin
2019-08-14 16:37:10 UTC (2 months ago)

Wronr reading of 16 bit tiff

On Wed, 2019-08-14 at 07:04 +0200, AndyJP wrote:

I try scanning to 48bit (16 bit per channel) TIFF

You could also try scanning as PNG, and see if that works.

Liam (slave ankh on IRC)

Liam Quin - web slave for https://www.fromoldbooks.org/
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2019-08-15 03:14:12 UTC (2 months ago)
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Wronr reading of 16 bit tiff

You could also try scanning as PNG, and see if that works.

Liam (slave ankh on IRC)

Afaik, only linear response (raw) mode supported by vuescan is tiff.

AndyJP (via www.gimpusers.com/forums)