Search found 102 matches

by Jason S
2017-11-26T09:43:58-07:00
Forum: Users
Topic: How do I change or set the variable name while generating a XPM file
Replies: 1
Views: 1725

Re: How do I change or set the variable name while generating a XPM file

As of v7.0.7-11, the pattern "static char *...[] = {" is hardcoded, and cannot be changed. The "..." is the "base output filename", and I don't see any way to set it independently. There must be many ways to automate the editing that you say you're doing manually. In a Unix-like environment, you cou...
by Jason S
2017-10-29T08:17:17-07:00
Forum: Users
Topic: Mimic Photoshop Bicubic Automatic Resampling
Replies: 8
Views: 5465

Re: Mimic Photoshop Bicubic Automatic Resampling

This is surely outdated, but I want to point out my writeup about Photoshop's algorithms from 2011.
by Jason S
2017-05-29T09:49:57-07:00
Forum: Developers
Topic: PNG eXIF chunk proposal
Replies: 9
Views: 12682

Re: PNG eXIF chunk proposal

One troublesome aspect was that the ImageMagick "Exif" property can contain
the JPEG thumbnail image, which isn't strictly a part of Exif.
I'm confused. A JPEG thumbnail image is definitely a standard part of Exif. Is there something special about the 'ImageMagick "Exif" property'?
by Jason S
2017-05-01T07:52:08-07:00
Forum: Bugs
Topic: Large image dimension causes slow dithering
Replies: 1
Views: 5109

Large image dimension causes slow dithering

I think it's the dither operation that's very slow when I create certain images with one very large dimension. The time it takes seems to be exponential (correction: quadratic) based on image's larger dimension, and jumps way up at each power of 2(?). Maybe there is a legitimate reason for this, but...
by Jason S
2017-02-15T12:11:55-07:00
Forum: Bugs
Topic: How to check whether image is old styled jpeg compression mode or New styled JPEG compression ?
Replies: 2
Views: 3566

Re: How to check whether image is old styled jpeg compression mode or New styled JPEG compression ?

Other than the warning message, I see nothing in the "identify -verbose" output that tells you this. It says "Compression: JPEG" either way. Outside of ImageMagick, you could use tiffinfo from libtiff ("Old-style JPEG" vs. "JPEG"), ExifTool ("JPEG (old-style)" vs. "JPEG"), or some versions of the Un...
by Jason S
2016-12-20T08:13:03-07:00
Forum: Users
Topic: jpg to jpeg2000
Replies: 2
Views: 2302

Re: jpg to jpeg2000

The test_q10.jp2 and test_jp2_q10.jp2 files from your dropbox link are not JPEG2000 files. They are regular JPEG files with an incorrect extension. I tried your commands (with a newer version of ImageMagick) and correctly got JPEG2000 files. However, a quality of 10 seems to be too low to get much m...
by Jason S
2016-10-27T09:00:27-07:00
Forum: Users
Topic: Convert to 32-bit depth BMP
Replies: 7
Views: 11671

Re: Convert to 32-bit depth BMP

BMP is limited to around 10 bits per channel (and more than 8 is rarely supported), so if you really want 32, you can't use BMP format. Assuming you want 32 bits per pixel : Most full-color BMP images have 24 bits per pixel, not 32. A 32-bit BMP could mean (1) there are 8 unused bits per pixel, or (...
by Jason S
2016-09-03T11:57:05-07:00
Forum: Bugs
Topic: TIFF to JPG, image comment lost
Replies: 4
Views: 4157

Re: TIFF to JPG, image comment lost

The tag we're talking about is 40092 (XPComment), not 59932 (PADDING_DATA). As far as I can tell, 40092 is not supported by IM. It does appear in the EXIFTOOL output above. Support for the tags 40091 through 40095 (and maybe some of 18246 through 18249) might be a nice feature, given that they are c...
by Jason S
2016-05-04T20:01:19-07:00
Forum: Bugs
Topic: Issue Re sizing Images with hidden alpha channels
Replies: 9
Views: 5953

Re: Issue Re sizing Images with hidden alpha channels

The image has 3 "extra samples" per pixel, all of which are labeled as containing "unspecified" data (i.e. not necessarily alpha samples). As far as I can tell, if a TIFF image has one or more extra samples, ImageMagick 6.x always guesses that one of them (I'm not sure which one) is an alpha channel...
by Jason S
2016-04-27T18:16:55-07:00
Forum: Users
Topic: ImageMagick Lacks Unicode Support??
Replies: 1
Views: 2062

Re: ImageMagick Lacks Unicode Support??

convert requires an output file, even with the -identify option. If you don't want that, try convert.exe 獅藝學會.jpg info: or identify.exe 獅藝學會.jpg ImageMagick on Windows can handle Unicode filenames on the command line. However, it does not correctly print Unicode to the console, so the filenames are ...
by Jason S
2016-02-17T15:33:33-07:00
Forum: Bugs
Topic: TGAs generated from Crazy Bump got vertically flipped after mogrify -resize
Replies: 3
Views: 3381

Re: TGAs generated from Crazy Bump got vertically flipped after mogrify -resize

Steps to reproduce, in 6.9.3-4 (-resize and -annotate are not necessary): convert NRM_Map.tga -resize 200x -annotate +20+20 "TGA" temp.tga convert temp.tga temp.png temp.tga and temp.png are flipped. It happens if the input and output formats are both TGA, and the input image has top-down orientatio...
by Jason S
2015-09-08T17:31:51-07:00
Forum: Users
Topic: Option for TGA format image origin
Replies: 5
Views: 6298

Re: Option for TGA format image origin

As far as I can tell, there is no such feature, as of ImageMagick 6.9.2-0. IM only ever sets the descriptor/attributes byte to 0, 1, or 8; so bits 5 and 4 are always 0, and the orientation is always bottom-left. (You said bottom-left is 01, but I'm pretty sure it's 00.)
by Jason S
2014-12-29T18:55:04-07:00
Forum: Bugs
Topic: exif orientation bug
Replies: 1
Views: 2457

Re: exif orientation bug

I think the correct link is http://needkane.qiniudn.com/error6.jpg.

It looks like a bug to me (tested with v6.9.0-2). The Exif thumbnail image has an Orientation tag, and I'm guessing that the -auto-orient routine wrongly thinks that tag applies to the main image.
by Jason S
2014-05-21T13:34:44-07:00
Forum: Bugs
Topic: Problem converting .mac files
Replies: 5
Views: 7190

Re: Problem converting .mac files

I propose this patch. It seems to fix it for me, at least. --- a/ImageMagick-6.8.9-1/coders/mac.c 2013-12-01 14:47:50.000000000 +0000 +++ b/ImageMagick-6.8.9-1/coders/mac.c 2014-05-21 17:59:00.393848099 +0000 @@ -244,6 +244,7 @@ } } pixels=(unsigned char *) RelinquishMagickMemory(pixels); + (void) S...
by Jason S
2014-05-17T13:06:49-07:00
Forum: Bugs
Topic: Problem converting .mac files
Replies: 5
Views: 7190

Re: Problem converting .mac files

valgrind reports a number of "Conditional jump or move depends on uninitialised value" issues when I convert a .mac file. If that's related, there may well be some randomness to it. (But for me, it seems completely deterministic on three completely different platforms with three completely different...