Legacy ImageMagick Discussions Archive

Glenn, I just sent you an email with a copy of the PNG I got back from v6.6.7-3.

Dave

I installed 6.6.7-3, and the TIFF to PNG conversions are indeed much faster - around 2.5 seconds for my 1700x2200 bi-tonal image. Unfortunately, the output image is unusable. If I view the PNG image with ImageMagick's display command at its native size, it looks fine. But if I try a resize to ...

Thanks for the update, Axel. I'll give it a try.

Dave

I tried setting -quality 20 and -quality 10. It inflated the size of the PNG file, but the performance was the same.

I notice that the PNG file is 8-bit, while my input TIFF is 1-bit. Can I force the PNG to be 1-bit as well, and would that possibly improve the performance?

Dave

Interesting. Which version of the PNG library is being used in 6.6.1? I currently have PNG 1.4.5 and ImageMagick 6.6.6-10.

Dave

I don't have a way to send a URL. Is there some way I can attach the TIFF, or email it somewhere?

Dave

I'm brand new to ImageMagick. My immediate need is to convert monochrome TIFF images to PNG on a Unix system, and I'm finding it to be much too slow. My test image is a black & white TIFF image from a 200 DPI scan of an 8 1/2 x 11 document (around 1700 x 2200 pixels). The TIFF file is around 20K. We ...