> For the complete documentation index, see [llms.txt](https://mostafaznv.gitbook.io/pdf-optimizer/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mostafaznv.gitbook.io/pdf-optimizer/advanced-usage/configuring-ghostscript/grayimagefilter.md).

# GrayImageFilter

| Method Name     | Argument Name | Argument Type                             |
| --------------- | ------------- | ----------------------------------------- |
| grayImageFilter | filter        | Mostafaznv\PdfOptimizer\Enums\ImageFilter |

Specifies the compression filter to be used for grayscale images. Ignored if <mark style="color:red;">AutoFilterGrayImages</mark> is true or <mark style="color:red;">EncodeGrayImages</mark> is <mark style="color:red;">false</mark>.