> For the complete documentation index, see [llms.txt](https://dazhizhong.gitbook.io/pixray-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dazhizhong.gitbook.io/pixray-docs/advanced/developing-a-custom-image-filter.md).

# Developing a custom image filter