Search found 37 matches

by gubach
2017-12-21T06:27:59-07:00
Forum: Users
Topic: pixel exact drawing and png
Replies: 4
Views: 1945

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: 1945

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: 1945

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: 8332

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: 8332

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: 8598

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: 18227

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...
by gubach
2017-02-15T02:06:26-07:00
Forum: Users
Topic: morphology operation that generate an additional compact border region around shapes
Replies: 21
Views: 8598

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

About the management of complex functions: In Matlab each complex function has its own m-file like conformalInverse_0001.h: function U = conformalInverse(X, ~) %#codegen U = [zeros(size(X))]; Z = complex(X(:,1),X(:,2)); % insert CM formula here a = 2; W = (1./(4 * Z.^a - 1)); % bipole 1/(4*z^2-1) U(...
by gubach
2017-02-14T05:16:31-07:00
Forum: Users
Topic: morphology operation that generate an additional compact border region around shapes
Replies: 21
Views: 8598

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

@fmw42: Have taken a look at the CM image examples: Very!!!! interesting because of -v vp ... VP is the virtual-pixel method. Any virtual-pixel method is allowed. The default=tile. It seems that a virtual-pixel method can avoid the empty black spaces that I am trying to fight with those post process...
by gubach
2017-02-14T02:27:01-07:00
Forum: Users
Topic: morphology operation that generate an additional compact border region around shapes
Replies: 21
Views: 8598

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

@fmw42: I am in the experimental and development phase; I have used for the published images the bipole CM a = 2; W = (1./(4*Z.^a - 1)); extracted from https://karczmarczuk.users.greyc.fr/TEACH/InfoGeo/Work/ComplexMapStill.jar I will look at the script and your proposal with -level soon. Thank you v...
by gubach
2017-02-13T12:50:43-07:00
Forum: Users
Topic: morphology operation that generate an additional compact border region around shapes
Replies: 21
Views: 8598

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

@ snibgo: the pictures were generated by conformal maps (a sub set of complex functions) for image distortion programmed in Matlab. IMs fx can not handle complex numbers so I had to look for an other environment. But now I have the problem that I can not duplicate the CopyOpacity+Over pipeline from ...
by gubach
2017-02-13T05:20:26-07:00
Forum: Users
Topic: morphology operation that generate an additional compact border region around shapes
Replies: 21
Views: 8598

morphology operation that generate an additional compact border region around shapes

I have a gray scale mask (https://www.flickr.com/photos/gbachelier/32061262473/in/dateposted-public/) that should be used in CopyOpacity to mask out regions with strong aliased edges (https://www.flickr.com/photos/gbachelier/albums/72157677436918822). My idea was to enlarge the black shapes of the m...
by gubach
2017-01-16T05:39:09-07:00
Forum: Developers
Topic: Mitchell interpolation definition
Replies: 3
Views: 7869

Re: Mitchell interpolation definition

Thanks snibgo and fmw42! Found this in resize.c and http://http.developer.nvidia.com/GPUGems/gpugems_ch24.html : static double CubicBC(const double x,const ResizeFilter *resize_filter) { /* Cubic Filters using B,C determined values: Mitchell-Netravali B = 1/3 C = 1/3 "Balanced" cubic spline filter C...
by gubach
2017-01-13T09:26:23-07:00
Forum: Developers
Topic: Mitchell interpolation definition
Replies: 3
Views: 7869

Mitchell interpolation definition

Hello, I want to define the Mitchell function as a custom interpolation kernel in Matlabs imresize (examples in http://stackoverflow.com/questions/8036019/matlab-imresize-with-a-custom-interpolation-kernel). First step would be the definition of the Mitchel filter and in http://www.imagemagick.org/U...
by gubach
2016-05-09T11:53:51-07:00
Forum: Developers
Topic: image distortion with conformal maps
Replies: 2
Views: 4366

image distortion with conformal maps

In several occasions I stumbled upon the possibility to distort images with conformal maps (for example with SeamlessMaker http://www.hypatiasoft.fr/) and I experimented with http://davidbau.com/conformal/ to get maps that might be interesting for distortion. Is fx expressive enough to define confor...