Search found 12691 matches

by snibgo
2020-02-19T17:27:46-07:00
Forum: Users
Topic: subtract only the luminance of two images?
Replies: 4
Views: 196

Re: subtract only the luminance of two images?

Subtracting one luminance from another will result in about half the values being negative. Is that what you really want? How about taking the difference, which is the absolute value of one minus the other. The hue channels can be averaged, but does that mean anything? I think averaging the a and b ...
by snibgo
2020-02-19T11:27:42-07:00
Forum: Developers
Topic: Append+ function on indexed images
Replies: 1
Views: 76

Re: Append+ function on indexed images

IM doesn't guarantee to do anything in particular with palettes. You could examine the source code to see what it happens to do currently and how it orders the entries, but that could change in future versions.

IM doesn't provide control of palettes for users. Gimp does.
by snibgo
2020-02-19T09:30:31-07:00
Forum: Users
Topic: watermark with extra info - loop needed
Replies: 2
Views: 122

Re: watermark with extra info - loop needed

Does your code work for a single file? I doubt it, as you have "*jpg" for both input and output for "magick convert". Do you want all four "magick convert" commands executed for every file? If so, why not combine them into just one command? This would save writing temporary lossy JPEGs. For v7, I su...
by snibgo
2020-02-19T09:24:59-07:00
Forum: Users
Topic: negate image w/ transparent.
Replies: 1
Views: 93

Re: negate image w/ transparent.

See the v7 porting doc: http://www.imagemagick.org/script/porting.php

The problem is that v6 by default would negate just the RGB. By default, v7 also negates alpha. So the fix (which works in both v6 and v7) is:

Code: Select all

convert trans.png -channel RGB -negate +channel negative.png
by snibgo
2020-02-19T09:19:48-07:00
Forum: Users
Topic: convert: NoImagesDefined
Replies: 7
Views: 259

Re: convert: NoImagesDefined

convert: unable to open image 'C\tex1_1024x256_F010ABC3EF3BF6A1_12.png': Permission denied @ error/blob.c/OpenBlob/3496. The operating system isn't giving you permission to open the file. What happens when you type just "C\tex1_1024x256_F010ABC3EF3BF6A1_12.png" (no quotes) at the command line? Does...
by snibgo
2020-02-19T05:34:58-07:00
Forum: Developers
Topic: no decode delegate for this image format
Replies: 3
Views: 202

Re: no decode delegate for this image format

What version of IM? In Python, leading spaces are significant. So when pasting Python code, please put it inside [ code ] and [ /code ] tags. I don't know why you have two "DELEGATES" lines. Please post the complete output of "convert -list configure" and "convert -version". Is Ghostscript installed...
by snibgo
2020-02-18T16:45:11-07:00
Forum: Users
Topic: convert: NoImagesDefined
Replies: 7
Views: 259

Re: convert: NoImagesDefined

C:\Users\henri\Desktop\ImageMagick-7.0.9-Q16>convert ... I expect that's the problem. You installed ImageMagick to a directory, but then moved that directory to your desktop, and now IM can't find its own files. If you really want IM to reside in a directory on your desktop, re-install IM and give ...
by snibgo
2020-02-18T15:24:45-07:00
Forum: Developers
Topic: Minor webpage documentation clarification for HDRI
Replies: 6
Views: 238

Re: Minor webpage documentation clarification for HDRI

Skygaze wrote:Suggested: "Building ImageMagick source for Windows requires a modern version of Microsoft Visual Studio IDE (free)"
I suggest changing "requires" to "can be done with". I've been building IM on Windows with GNU tools for years, without "requiring" MS VS.
by snibgo
2020-02-18T10:35:03-07:00
Forum: Users
Topic: Jaggy results with using maps for perspective transform
Replies: 17
Views: 560

Re: Jaggy results with using maps for perspective transform

If you double the size, you effectively get one more bit of precision, so 9 instead of 8. If you supersample by a factor of 8, that is an extra 3 bits, so 11 instead of 8. In my link I show we generally need at least 8 more bits, so 16 instead of 8. To get this by supersampling, you would need to re...
by snibgo
2020-02-18T09:03:20-07:00
Forum: Users
Topic: white bleeding in pdf files
Replies: 2
Views: 167

Re: white bleeding in pdf files

What is your IM command? With Adobe Acrobat Reader, I can't see a thin white line on your PDF.
by snibgo
2020-02-18T08:53:47-07:00
Forum: Users
Topic: EXR to DDS?
Replies: 3
Views: 179

Re: EXR to DDS?

Sorry, I know nothing about DDS formats. See the DDS entry in https://www.imagemagick.org/script/formats.php . I suspect DDS is integer-only.
by snibgo
2020-02-18T07:38:23-07:00
Forum: Users
Topic: EXR to DDS?
Replies: 3
Views: 179

Re: EXR to DDS?

I suppose your DDS "R16G16B16A16" is an integer format. EXR HDR images are high dynamic range, which means some values are greater than the usual QuantumRange (65535 or whatever). Those values can't be put in an integer file format. Of course, the values can be reduced so they are no longer greater ...
by snibgo
2020-02-18T07:27:00-07:00
Forum: Developers
Topic: Problem with IM version TIF to PNG
Replies: 2
Views: 123

Re: Problem with IM version TIF to PNG

Please upload a sample input and output to somewhere, and paste links here.
by snibgo
2020-02-17T19:29:15-07:00
Forum: Digital Image Processing
Topic: Any recom for HDR (6x2EV) and batch proc?
Replies: 16
Views: 1135

Re: Any recom for HDR (6x2EV) and batch proc?

Hmmm, a bit puzzled... saturated sensels output gives me MIN=1.30025e+08 MAX=1.03037e+09 SAT_PC=100 which in a way makes sense since at 14-bit (Canon CR2) I am asking for pixels brighter than 16383. But min 1.30025e+08 ! You are doing something wrong. dcraw can make 8-bit or 16-bit integer files. T...
by snibgo
2020-02-17T15:16:51-07:00
Forum: Users
Topic: Jaggy results with using maps for perspective transform
Replies: 17
Views: 560

Re: Jaggy results with using maps for perspective transform

See also Straightening horizons: How much precision?. I did those tests with IM v6. They show that Q8 integer is really horrible, Q16 integer or HDRI is better, but Q32 is best for that example.