to use OpenMP, do i need to have OpenMP insaled or just by having OpenMP as feature is enough?

[ghost]

OpenMP is something inside ImageMagick or i need to install OpenMP from the repository too?

[dlemstra]

Which OS are you on?

[ghost]

Arch Linux

[urban-warrior]

OpenMP is typically a delegate library or part of the compiler build chain. It is not part of the ImageMagick distribution other than it is enabled if detected @ ImageMagick build time.

[ghost]

so i do need to install OpenMP right?

[urban-warrior]

Depends on the compiler. Some compilers have OpenMP built-in. Others depend on libgomp. If all goes well with the ImageMagick build, you can verify OpenMP support by checking the build features:

convert --version | grep Features
Features: Cipher DPC HDRI Modules OpenMP(4.5) TCMalloc

[ghost]

yes i have the feature
so ImageMagick is already using it?

[urban-warrior]

If OpenMP is an enabled feature, ImageMagick will use it wherever there is support for it... mostly the image processing algorithms. Reading and writing of an image is still single threaded.