Question 1

How do I install magick on macOS or Windows?

Accepted Answer

The README only provides Ubuntu instructions; for other OS, you need to manually install LuaJIT and the MagickWand/GraphicsMagick libraries using tools like Homebrew on macOS or compiling from source, which can be more involved.

Question 2

What's the difference between ImageMagick and GraphicsMagick when using magick?

Accepted Answer

ImageMagick and GraphicsMagick have similar interfaces but differ in features and performance; magick allows switching via require statements, but you can't use both in the same process due to C namespace collisions, so choose based on your project's needs.

Question 3

How to convert an image to WebP format with magick?

Accepted Answer

Load the image, use `set_format('webp')` to change the format, and set WebP-specific options with `set_option`, then save or get the blob. This leverages the underlying library's WebP support, but options may vary between ImageMagick and GraphicsMagick.

Question 4

Is magick better than calling ImageMagick CLI from Lua scripts?

Accepted Answer

Magick integrates directly into Lua, avoiding shell calls and enabling in-memory processing, which is more efficient for programmatic use. However, CLI tools might be simpler for one-off tasks or if you need the full command-line feature set.

Question 5

How to handle memory leaks when processing many images?

Accepted Answer

The library uses garbage collection, but for batch processing, manually call `destroy` on images after use to free memory immediately, as recommended in the README. This helps prevent high memory usage in long-running scripts.

Question 6

Can I use magick with OpenResty or other LuaJIT forks?

Accepted Answer

Yes, magick works with any LuaJIT environment, including OpenResty, as noted in the changelog where tests run on OpenResty's LuaJIT fork. Ensure the native Magick libraries are installed in that environment.

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