Gmic-Sharp - A .NET wrapper for libgmic

Software G'MIC
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I noticed that there did not appear to be any existing .NET Platform bindings for libgmic, so I decided to write one.
I also had a request on the Paint.NET forum from a G’MIC filter developer for a way to call the G’MIC API from a Paint.NET plugin.

Please note that this is currently a beta version.
It currently only targets Windows and the .NET Framework, but it should be possible for it to work with .NET Core on Linux / macOS.
This would require changing the gmic-sharp code to use the correct native library name for each platform.

The wrapper consists of a 32-bit and 64-bit C++ libraries that wrap libgmic, and a managed library written in C# that calls into the appropriate C++ library for the current platform.
There is a Windows-based sample application that demonstrates the use of the library.

gmic-sharp-native provides the native interface between gmic-sharp and libgmic.

gmic-sharp is the library that .NET application use to call G’MIC.

gmic-sharp-example is the Windows-based sample application that demonstrates the use of gmic-sharp.

gmic-sharp-native uses the same dual-license as libgmic (CeCILL v2.1 or CeCILL-C v1), this makes it simpler to statically-link the Windows DLLs to G’MIC.
Both gmic-sharp and gmic-sharp-example use the MIT/X11 license, same as .NET Core.

3 Likes
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That is really interesting!
I’d like to share these links from the G’MIC webpage.
We also have a Python binding almost ready for the libgmic. So, it seems a perfect timing to make both appear on the webpage, and communicate about alternative bindings.
What do you think ?

I don’t have a Windows machine right here to test unfortunately. Would it be possible to have a screenshot of the example application running, that I could put on the webpage ?

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That would be fine with me.

I added a note to my first post that the library is a Beta version.

I have been investigating Linux and macOS support for the gmic-sharp library, the main issue I see is that .NET Core does not currently have a built-in API for processing images that is can be used on all of its supported operating systems.

Here you go: gmic-sharp-example/images/GmicSharpExample.png at master · 0xC0000054/gmic-sharp-example · GitHub

1 Like
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Excellent news as I can convert even more filters in theory. I noticed you haven’t crossposted to pdn forum.

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This library is still a beta version, I want to get the final API figured out before anything takes a dependency on it.

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Released beta version 0.6.0.

  • Added a GdiPlusGmicBitmap(Image) constructor overload.
  • Improved type-safety for the Gmic class, it now uses a generic parameter to specify the GmicBitmap class that is in use.
  • The IGmicOutputImageFactory now uses a generic parameter to specify the GmicBitmap class that is in use.

See the Changelog for more information on the other changes.
Also updated the Readme to list the library features.

7

Released beta version 0.7.0.

  • Added support for changing the host application name seen by G’MIC scripts
  • Added support for running on Linux and macOS when using .NET Standard 2.1
  • The CustomResourcePath property now supports paths with non-ASCII characters

See the Changelog for more information on the other changes.

Added a cross-platform example application, gmic-sharp-cli-example.
It is a .NET Core 3.1 Console application that mimics gmic-cli.
The current release includes native binaries for the following operating systems:

Ubuntu 20.4 64-bit (x64)
Microsoft Windows 64-bit (x64)
Microsoft Windows 32-bit (x86)

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@PDN_GMIC I don’t know where to report this via github since there’s gmic-sharp-native,gmic-sharp,gmic-sharp pdn. So… When I tried doing this.

                string command = string.Format(CultureInfo.InvariantCulture,
                                               "m \"gmic_pdn_shape_circle: shape_circle $\"\"1\"" +
                                               "gmic_pdn_shape_circle 100 f.. i0#-1*255 k[0]");

Just a black image. Not even a circle there.

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What it the equivalent G’MIC CLI command?
My guess is that it may be a formatting error.

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rep_test_pdn:
m "gmic_shape_circle: shape_circle $""1"
gmic_shape_circle 100 f.. i0#-1*255 k[0]

$ sp , rep_test_pdn

outputs a circle of 100 px in the corner.

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I am getting a format exception whenever I run that command.

 *** Error in ./ *** Command 'f': Invalid selection [-2] (contains index '-2', not in range -1...0)

I also had to use a StringBuilder to get the first line properly formatted.

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Did you add a image before running rep_test_pdn command? Should work.

EDIT: Also, the first line of rep_test_pdn is properly formatting in g’mic-cli. On context of gmic-c#, what’s the line looks like after stringbuilder?

image

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m "gmic_pdn_shape_circle: shape_circle $""1"gmic_shape_circle 100 f.. i0#-1*255 k[0]
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Try this:

m "gmic_pdn_shape_circle: shape_circle $""1" gmic_pdn_shape_circle 100 f.. i0#-1*255 k[0]

This actually worked on PDN. I’m not sure why the others don’t work.

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That works.
Here is the StringBuilder code for reference.

StringBuilder sb = new StringBuilder("m ");
sb.Append('"').Append("gmic_pdn_shape_circle: shape_circle$").Append('"').Append('"').Append('1').Append('"');
sb.Append(" gmic_pdn_shape_circle 100 f.. i0#-1*255 k[0]");
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Now I see why the others don’t work. They need a space on the beginning of new line for it to work. That is not convenient, but I can work with it though.

\n will also work.

@PDN_GMIC Just one more thing. What I supposed to do when I have to use {} characters within the g’mic parser? I know that {} are reserved for c# to.string, so, I’m wondering if there is a workaround.

EDIT: Using double brackets is the escape. Had to search for a solution for a while.