Search found 45 matches

by gubach
2019-08-24T06:24:48-07:00
Forum: Users
Topic: reproducing Spherical Distortion Map
Replies: 9
Views: 2062

Re: reproducing Spherical Distortion Map

@snibo: in the forth post I had difficulties in reproducing sphere_overlay.png from the sphere_mask.png using the givien code; I go a very different looking grayscale image. But for test purpes I upscaled the thumbnail in the Usage-page for a HardLight compositing test. But after I saw the very poor...
by gubach
2019-08-21T04:05:06-07:00
Forum: Users
Topic: reproducing Spherical Distortion Map
Replies: 9
Views: 2062

Re: reproducing Spherical Distortion Map

I found the reason why the sphere is smaller: Because the run time of the sphere_lut generation is very high even in the 1500x1500 test case I generated a smaller version and upscaled the png later. This is obviously not compatible with the later usage of sphere_lut as a displacement map with -fx "p...
by gubach
2019-08-21T03:21:47-07:00
Forum: Users
Topic: reproducing Spherical Distortion Map
Replies: 9
Views: 2062

Re: reproducing Spherical Distortion Map

Apart from the HardLight and CopyOpacity compositing I tested the actual spherical projection (or simulation of it) with convert in.jpg sphere_lut.png -fx "p{ v*w, j }" out.jpg and I got an interesting Glitch Art image: https://www.flickr.com/photos/gbachelier/48591195817. A sphere'ish shape is reco...
by gubach
2019-08-21T01:16:35-07:00
Forum: Users
Topic: reproducing Spherical Distortion Map
Replies: 9
Views: 2062

Re: reproducing Spherical Distortion Map

I am now on the third step "sphere_overlay". This line "C:\Program Files\ImageMagick-6.9.7-Q8\convert.exe" sphere_mask.png ( +clone -blur 0x20 -shade 110x21.7 -contrast-stretch 0% +sigmoidal-contrast 6x50% -fill grey50 -colorize 10% ) -composite sphere_overlay.png generates no errors but an image th...
by gubach
2019-08-21T00:10:23-07:00
Forum: Users
Topic: reproducing Spherical Distortion Map
Replies: 9
Views: 2062

Re: reproducing Spherical Distortion Map

Hello mw42,
thanks for answering. Works now fine!
by gubach
2019-08-20T11:21:40-07:00
Forum: Users
Topic: reproducing Spherical Distortion Map
Replies: 9
Views: 2062

reproducing Spherical Distortion Map

I am trying to reproduce the steps for generating a Spherical Distortion Map (http://www.imagemagick.org/Usage/mapping/#spherical). I am calling IM with this string in direct analogy to the given one in the text: "C:\Program Files\ImageMagick-6.9.7-Q8\convert.exe" -size 1500x1500 xc: -channel R -fx ...
by gubach
2019-07-25T23:55:32-07:00
Forum: Developers
Topic: Formalizing ModulusAdd and ModulusSubtract
Replies: 4
Views: 1807

Re: Formalizing ModulusAdd and ModulusSubtract

Is the interpretion of the code in "case ModulusAddCompositeOp" correct, that if pixel (= Sc + Dc; why not Sca + Dca like in the SVG specification?) is larger than QuantumRange (= 1) or smaller than 0 (which is equivalent to pixel is in the interval [0 1]) the equation pixel=(Sa*Da*pixel+Sa*Sc*(1.0-...
by gubach
2019-07-22T00:38:23-07:00
Forum: Developers
Topic: Formalizing ModulusAdd and ModulusSubtract
Replies: 4
Views: 1807

Formalizing ModulusAdd and ModulusSubtract

I am trying to formalize ModulusAdd and ModulusSubtract (see http://www.imagemagick.org/Usage/compose/#modulus_add and the discussion https://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=28186&p=124698&hilit=ModulusAdd#p124698) with the known image symbols Sca, Dca, Sa, Da (from http://w...
by gubach
2017-12-21T06:27:59-07:00
Forum: Users
Topic: pixel exact drawing and png
Replies: 4
Views: 2608

Re: pixel exact drawing and png

I need a black hull/shell around a white polygon with a specified thickness. If those polygons are composed together with no overlap this simulates a controlled gap artifact (see https://www.flickr.com/photos/gbachelier/27419431099) that can be used as a mask to correct such kind of artifacts in a c...
by gubach
2017-12-21T05:17:51-07:00
Forum: Users
Topic: pixel exact drawing and png
Replies: 4
Views: 2608

Re: pixel exact drawing and png

So I think it is better to forget the stroke command and adapt the coordinates to simulate a kind of shrinking or pushing them away from the image edges. For a strokewidth=1 this would be 1,1 999,999 1,999. But how can this adaption be made for arbitrary polygons? Ad hoc I would dissect the image in...
by gubach
2017-12-20T14:22:33-07:00
Forum: Users
Topic: pixel exact drawing and png
Replies: 4
Views: 2608

pixel exact drawing and png

If I am drawing a triangle with "C:\Program Files\ImageMagick-6.9.7-Q8\convert.exe" -size 1000x1000 xc:black -fill white -stroke black -strokewidth 2 -draw "polygon 0,0 1000,1000 0,1000" intermed_mask.png and open the png (in PS) I see an unexpected result: looking at the lower left corner I see on ...
by gubach
2017-03-07T05:44:50-07:00
Forum: Developers
Topic: Infos about virtual-pixel method tile
Replies: 5
Views: 9657

Re: Infos about virtual-pixel method tile

Thanks for the link. I am interested how the algo identifies pixel that should be set/changed via a virtual pixel method (VPM). Is it possible to externalize those pixels given the following task: Given are an image I and a grayscale mask M with the same h x w. Task: Change all pixel coordinates in ...
by gubach
2017-03-06T04:25:09-07:00
Forum: Developers
Topic: Infos about virtual-pixel method tile
Replies: 5
Views: 9657

Infos about virtual-pixel method tile

I am interested in the virtual-pixel method tile (and perhaps mirror) and I would like to look at algorithms and/or source code. Can anyone help? Thank you very much!
by gubach
2017-02-15T14:03:08-07:00
Forum: Users
Topic: morphology operation that generate an additional compact border region around shapes
Replies: 21
Views: 10227

Re: morphology operation that generate an additional compact border region around shapes

@fmw42: > Too much effort for me to manually separate the real and imaginary components of all your expressions or even the more complicated ones. I had a look at your script and the transformation of a textbook expression to your syntax is indeed difficult. I have made a first experiment to compare...
by gubach
2017-02-15T05:22:28-07:00
Forum: PerlMagick
Topic: Install ImageMagick on Strawberry Perl on Win 10
Replies: 2
Views: 20608

Re: Install ImageMagick on Strawberry Perl on Win 10

Installing PerlMagick@Win makes me mad: tested the newest combination strawberry-perl-5.24.1.1-64bit and ImageMagick-7.0.4-8-Q16-x64-dll and the "notest install Image::Magick"-strategy did not work! (PerlMagick not found in @INC) So I installed an old combination strawberry-perl-5.20.2.1-64bit and I...