Search found 4 matches

by UDTP
2019-06-13T09:11:58-07:00
Forum: Bugs
Topic: Problem with Group 4 compression on B&W TIFF
Replies: 10
Views: 3918

Re: Problem with Group 4 compression on B&W TIFF

I'm forced to use group4 compression in order to meet standards over which I have no control. If I had my way these would be served up as low quality JPEG's since the only thing of matter in them is the content. But I'm not the one making the rules and that is life; I'm doing what I'm told not neces...
by UDTP
2019-06-13T07:05:11-07:00
Forum: Bugs
Topic: Problem with Group 4 compression on B&W TIFF
Replies: 10
Views: 3918

Re: Problem with Group 4 compression on B&W TIFF

The color image is upsampled with bicubic and then converted to bi-level. The example image I posted is a bi-level image and one of the files I am trying to apply the compression to. The worst case described in the wiki article is, I think, a checkerboard pattern. I can see that as an issue with som...
by UDTP
2019-06-12T21:41:20-07:00
Forum: Bugs
Topic: Problem with Group 4 compression on B&W TIFF
Replies: 10
Views: 3918

Re: Problem with Group 4 compression on B&W TIFF

The image was upsampled (400->600 DPI) prior to the conversion from color to B&W using photoshop's default bicubic interpolation. But no changes are made to the image after conversion to B&W other than my attempt to apply compression. I've never run into this issue before despite having worked with ...
by UDTP
2019-06-12T13:53:13-07:00
Forum: Bugs
Topic: Problem with Group 4 compression on B&W TIFF
Replies: 10
Views: 3918

Problem with Group 4 compression on B&W TIFF

Greetings. I'm running ImageMagick 7.0.8-49 portable Q16 x64 on Windows 10. I'm trying to apply Group4 compression to a folder full of bi-level (1bit) TIFF images using the command "convert -compress Group4 [input file] [output file]" When I run it, file size increases anywhere between 200-300%. So ...