Legacy ImageMagick Discussions Archive

I have now done both operations. The image that was processed with -filter point seems to have the same number of colors as the original. I can't open the full original image, but an image that combines two tiles from it with especially bright and dark points has 153 shades, while the resized image ...

Nearest neighbor does the same thing? Heck. This was not mentioned, and is rather important. Processing that way has completed, and to the naked eye doesn't have problematic artifacts, after a quick inspection, but that certainly doesn't mean there aren't any. There are indeed sudden tonal changes ...

Ah, looking at the explanation of -sample revealed the method i'd prefer, though it takes longer: The results are thus equivalent to using -resize with a -filter setting of point (nearest neighbor), though -sample is a lot faster, as it avoids all the filter processing of the image. As such it ...

I wish i knew how to resize this image without changing the gray tones. The file sizes have ballooned up tremendously in the tiles from the resized image, but the tile dimensions taken from the image of original size are problematic for use in 3d models. They are really supposed to have dimensions ...

Well, an experiment where i created one tile from the original TIFF yielded a file even smaller than the one taken from the MPC, 6.1 MB versus 7.3 MB - so no explanation there. And it took over half an hour. You are right that the rescaling added colors. Lots of them. Tile from image B, derived by ...

The source is in both cases the same GeoTIFF file, which is a grayscale image depicting a heightmap of the Moon. The only difference is in one case i scaled that file down to 65536 x 32768 before slicing it into tiles - let's call it image A, while in the other case, image B, i left it it's original ...

Yeah, but they are ALL around that size, while the images that are 8192 px on a side are ALL around 40 MB

I am listing in MB in all cases, as reported by my file system. Compression levels weren't set in any of these operations.

I have taken a grayscale TIFF that measures 92160 x 46080, converted it into MPC format, and created 32 tiles from that image, converted into PNG format. Each tile is a square 11.520 px on a side. But the tiles are only between 6 and 11 MB each. GIMP reports they are indeed 16-bit grayscale, and ...

I have now managed to create a 16-bit png image that is 65,536 x 32,768 and 1.5 GB. I thought about stretching the grayscale out with auto levels, but it seems that for the displacement map or bump map purposes of this image, the way it is is better. The image is available for download at https ...

This issue has now been completely resolved with an answer to my question about it on AskUbuntu.SE, here - https://askubuntu.com/a/1042482/364597.

Some help with installing delegates on Ubuntu was in this answer - https://askubuntu.com/a/746195/364597 - but it is outdated now. There still is no TIFF delegate, and many other gaps. This is proving difficult, i've been at it all day. I am going to work on it for another half-day or so, and if ...

Do I need to uninstall it then, or can I now install the delegates after the fact?

Alright, you said i must install them first, so i'm taking it i should uninstall IM, get the delegates i need, and then reinstall it.

Oh, just saw your latest reply. Let me work through that.

$ magick identify --version Version: ImageMagick 7.0.7-37 Q16 x86_64 2018-05-31 https://www.imagemagick.org Copyright: © 1999-2018 ImageMagick Studio LLC License: https://www.imagemagick.org/script/license.php Features: Cipher DPC HDRI OpenMP Delegates (built-in): $ magick identify LOLA-Center- ...

Okay, the test-suite still fails twice, on the same tests.

Config.log is pretty long. Shall i post it somewhere so you can look at it? Is there something in particular in it i can post here?