Search found 279 matches

by whugemann
2019-03-26T01:31:15-07:00
Forum: Bugs
Topic: disappointed by -define jpeg:preserve-settings results
Replies: 10
Views: 5704

Re: disappointed by -define jpeg:preserve-settings results

I think that only the programmers could really answer that question. My impression is that this option just does nothing at the moment. Perhaps one could re-define it in a way that it really does what it claims, i.e. leaving everything, including the DQTs, untouched. Checking out the other options, ...
by whugemann
2019-03-25T03:25:55-07:00
Forum: Bugs
Topic: disappointed by -define jpeg:preserve-settings results
Replies: 10
Views: 5704

Re: disappointed by -define jpeg:preserve-settings results

The documentation is out-of-date. We preserve sampling factor and image quality but not the quantization tables. The Usage page https://www.imagemagick.org/Usage/formats/#jpg_write still hasn't got it quite right IMHO, as it skips the point that these settings are kept automatically. However: Why i...
by whugemann
2019-03-22T10:01:22-07:00
Forum: Developers
Topic: SET DQT via -define jpeg:q-table
Replies: 1
Views: 1881

SET DQT via -define jpeg:q-table

I have just been experimenting with this option on my Windows computer, running IM 7.0.8-23 Q16 x64: magick -size 256x256 -depth 8 -seed 1000 plasma:fractal -define jpeg:q-table="C:\Temp\Erich\table.xml" plasma_my.jpg checking the DQT afterwards with JPEGsnoop (https://www.impulseadventure.com/photo...
by whugemann
2019-01-25T05:19:02-07:00
Forum: Developers
Topic: Estimating JPEG Quality
Replies: 1
Views: 2283

Re: Estimating JPEG Quality

I took a closer look at the code and found out myself: Basically, IM calculates the sum of all DQT entries and compares it directly to the sum of the IJG table entries, which is pre-calculated and stored in the vector sums[101]. The same is done for the sums of the two table entries no. 2 and 53, wh...
by whugemann
2019-01-22T02:26:27-07:00
Forum: Developers
Topic: Estimating JPEG Quality
Replies: 1
Views: 2283

Estimating JPEG Quality

I would like to know how IM estimates the JPEG Quality. I took a look at the code in jpeg.c, and it obviously calculates it from the DQT (around line 922). I know about the way how quality is translated into DQT as suggested by the IJG. But to my knowledge the IJG made no suugestion for the other wa...
by whugemann
2019-01-07T06:50:26-07:00
Forum: Developers
Topic: CLAHE - no real value for clip-limit?
Replies: 3
Views: 2652

CLAHE - no real value for clip-limit?

I have just noticed that IM obviously accepts only integer values for the clip-limit, i.e. the contrast limit. Why that? I have used values between 2.0 and 3.0 quite frequently with Fiji in the past, with 2.0 producing a rather natural look, 3.0 a significantly artificial look and anything between, ...
by whugemann
2018-12-25T11:17:00-07:00
Forum: Developers
Topic: IM Example Contributions (How To)
Replies: 8
Views: 35583

Re: IM Example Contributions (How To)

Well, I'm not offering to transfer all pages to a MediaWiki, but I would offer to set up a MediaWiki with a basic structure and transfer my own pages as a start. Doing so, I would rather split up the Windows page into several pages, as all Usage pages are way too long for Web pages, I guess. After t...
by whugemann
2018-12-25T01:41:10-07:00
Forum: Developers
Topic: IM Example Contributions (How To)
Replies: 8
Views: 35583

Re: IM Example Contributions (How To)

What is the future of Anthony's example section of the IM Website? Some years ago, I contributed http://www.imagemagick.org/Usage/windows/ http://www.imagemagick.org/Usage/lens/ to it, providing pure HTML code. I understand that this workflow will not work anymore. I think that especially the Window...
by whugemann
2018-12-18T10:31:23-07:00
Forum: Users
Topic: Excel VBA Clipboard issue
Replies: 10
Views: 5034

Re: Excel VBA Clipboard issue

I've just tested that IM has no problems converting WMF into something else – well at least pure vector WMF. It however doesn't convert WMFs from the clipboard. When you address the clipboard, IM obviously expects a raster image. An msoPicture is a Microsoft Office specific data format that IM canno...
by whugemann
2018-12-17T04:47:03-07:00
Forum: Users
Topic: Excel VBA Clipboard issue
Replies: 10
Views: 5034

Re: Excel VBA Clipboard issue

Your code results in different data formats stored in the clipboard. You can see this within Excel if you choose 'Paste special': Sheets("External Data").Shapes("Pole_Mark").Copy results in several formats beeing copied to the clipboard, the topmost being a raster image. Sheets("External Data").Shap...
by whugemann
2018-12-17T04:23:04-07:00
Forum: Users
Topic: Porting Windows batch files to IM version 7
Replies: 4
Views: 3985

Re: Porting Windows batch files to IM version 7

My own solution is to install both versions: v7 without legacy, and v6. Then "convert" runs v6, and "magick" (not "magick convert") runs v7. Am I right that the ordering in the PATH environment variable matters? After I installed IM7 (without legacy support), identify was no longer functioning, as ...
by whugemann
2018-12-03T03:34:08-07:00
Forum: Digital Image Processing
Topic: Native CLAHE support
Replies: 16
Views: 10782

Re: Native CLAHE support

OK, I have just verified that it is fixed in the current version 7.0.8-15. But I still cannot see any inluence of the clip-limit parameter. In Fiji/ImageJ its influence is quite drastic, the default value beeing 3.0. In ImageMagick, I cannot see any difference, regardless what value I supply for it....
by whugemann
2018-12-03T02:18:13-07:00
Forum: Users
Topic: Porting Windows batch files to IM version 7
Replies: 4
Views: 3985

Re: Porting Windows batch files to IM version 7

My own solution is to install both versions: v7 without legacy, and v6. Then "convert" runs v6, and "magick" (not "magick convert") runs v7.
Well, that sounds like a plan to me. I will take this road too (and report where it has led me ...)
by whugemann
2018-12-01T06:17:23-07:00
Forum: Users
Topic: Porting Windows batch files to IM version 7
Replies: 4
Views: 3985

Porting Windows batch files to IM version 7

Is there anywhere a hands-on approach to what I have to do exactly when migrating my batch files to IM version 7? Do I just have to click the checkboxes for legacy support during installation and may I then expect my batch files to run mostly? I read http://www.imagemagick.org/script/porting.php, bu...
by whugemann
2018-11-29T07:36:37-07:00
Forum: Digital Image Processing
Topic: Native CLAHE support
Replies: 16
Views: 10782

Re: Native CLAHE support

OK, got it. It would help if one would know about the default values and the range for the maximum contrast parameter. Usage: magick in.jpg -clahe 4x3+127+3 out.jpg or, basically: magick in.jpg -clahe 4x out.jpg I think there is a bug in the filter, as it produces diagobal stripes if the tiles are n...