[solved] black and white only tif image shows grey

[lian]

Hello, I have a strange problem with only black and white tif images I create (under Affinity Photo or Krita) - Greyscale 8 bits. I’m used to check the result in XnViewMP and I discovered that XnViewMP shows grey in the image. Did I miss some setting ?

[cday]

Are you able to upload an example TIFF image output from Affinity Photo or Krita?

And if the images are pure black and white, why output them as Greyscale 8-bit, rather than as TIFF 1-bit files with (for example) 'Fax' CCITT G4 compression, which is lossless and should result in much smaller files if that matters?

[lian]

Sorry, I forgot to attach the image.

test-bw-krita.tif

(746.88 KiB) Downloaded 46 times

And if the images are pure black and white, why output them as Greyscale 8-bit, rather than as TIFF 1-bit files with (for example) 'Fax' CCITT G4 compression, which is lossless and should result in much smaller files if that matters?

In these softwares, there are no 1-bit export ability.

[cday]

XnView MP Image > Count colors used indicates that your image has only two colours, as you stated. And your file has an 8-bit depth, again as you stated. But on my screen it displays as pure black and white, so I'm not sure why it displays with grey on your screen, other than that you are viewing it on a different screen.

After resaving your file with TIFF G4 compression, the file size is as predicted substantially reduced, from 756 KiB to 44.33 KiB.

And after converting the file to 1-bit depth, the size when saved with CCITT G4 compression is further reduced to only 2.37 KiB -- I said it could probably be substantially smaller...

test-bw-krita_8-bit_CCITT_G4.tif

(44.33 KiB) Downloaded 27 times

test-bw-krita_1-bit_CCITT_G4.tif

(2.37 KiB) Downloaded 66 times

[lian]

Yes, I’m aware I can have a smaller file but there is no utility for me as I have to work with them in Krita or another software that do not manage 1 bit images, it’s not useful.

I attach what I see when I zoom on the image in XnViewMP.

[cday]

I attach what I see when I zoom on the image in XnViewMP.

You see significant grey in that image on your screen?

If you view a 1-bit image that is sure to include pure black, if it doesn't look black and white it can only be due to the characteristics of the screen you are using. The average LCD screen doesn't render colours very accurately, if you read laptop and monitor reviews. No problem on my laptop screen, though, which I know generally doesn't have accurate rendering. Have you tried cleaning your screen?

[XnTriq]

I attach what I see when I zoom on the image in XnViewMP.

Please change High zoom quality in Tools → Settings… → View → View to Never.

• Correct: Image → Count colors used = 2
• Misleading: Image → Properties… → Properties → Image → Colors used = 256 (color depth)

[lian]

I attach what I see when I zoom on the image in XnViewMP.

Please change High zoom quality in Tools → Settings… → View → View to Never.

Thanks. I hoped there was a setting like this I did not know.