> ## Documentation Index
> Fetch the complete documentation index at: https://docs.filecheck.io/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Images

> Image checks in a PDF preflight profile — effective resolution, compression, color space, and bit depth of images placed inside the PDF.

The **Images** section checks raster images *placed inside a PDF* (not standalone image uploads — those use a [Raster profile](/configuration/preflight/raster)). Effective resolution is measured at the image's placed size, so a high-megapixel photo scaled up on the page can still fail. Each check lists its **action**, **settings**, and the messages the customer sees. See the [profile overview](/configuration/preflight) for how actions work.

## Minimum Resolution

The lowest acceptable effective resolution (DPI) at print size.

| Field        | Detail                                                                                                                                               |
| :----------- | :--------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Action**   | Warn                                                                                                                                                 |
| **Settings** | Minimum (dpi, default 150)                                                                                                                           |
| **Issue**    | One or more images are too low-resolution (`{actual.min}` DPI) and will look blurry in print. The minimum is `{target.effective}` DPI at print size. |
| **Fix**      | Replace the low-resolution images with higher-resolution versions and re-upload.                                                                     |

## Maximum Resolution

Flag images that are unnecessarily high-resolution, which bloat the file without improving print.

| Field        | Detail                                                                                                                             |
| :----------- | :--------------------------------------------------------------------------------------------------------------------------------- |
| **Action**   | Auto-fix                                                                                                                           |
| **Settings** | Warn above (dpi, default 600)                                                                                                      |
| **Issue**    | Some images have higher resolution than needed (`{actual.max}` DPI), which makes your file larger without improving print quality. |
| **Fix**      | Downsample the oversized images and re-upload.                                                                                     |
| **Auto-fix** | We'll downsample the oversized images automatically before printing.                                                               |

## Image Color Mode

Which color spaces are allowed for placed images. To convert image colors, use **Colors → Document Color Mode** with "Convert all" (dedicated image auto-fix here is coming soon).

| Field        | Detail                                                                                                                            |
| :----------- | :-------------------------------------------------------------------------------------------------------------------------------- |
| **Action**   | Warn                                                                                                                              |
| **Settings** | Allowed (CMYK / Grayscale / RGB)                                                                                                  |
| **Issue**    | One or more images are in `{actual.colorspaces}` color space, but we require images to be in `{target.allowed}` for this product. |
| **Fix**      | Convert the images to `{target.allowed}` and re-upload.                                                                           |

## Image Compression

Which image compression formats are supported.

| Field        | Detail                                                                               |
| :----------- | :----------------------------------------------------------------------------------- |
| **Action**   | Warn                                                                                 |
| **Settings** | Disallowed (JPEG, JPEG 2000, Flate/Zip, LZW, CCITT, JBIG2, Uncompressed)             |
| **Issue**    | Your file contains images saved with a compression format we don't support.          |
| **Fix**      | Re-save the images with a supported compression format and re-upload.                |
| **Auto-fix** | We'll re-encode the images with supported compression automatically before printing. |

## Bit Depth

The minimum color bit depth required for images, to avoid banding.

| Field        | Detail                                                                                                    |
| :----------- | :-------------------------------------------------------------------------------------------------------- |
| **Action**   | Reject                                                                                                    |
| **Settings** | Minimum (1 / 2 / 4 / 8 / 16 bit, default 8)                                                               |
| **Issue**    | One or more images have too low a color depth, which can cause banding. Use `{target.min}`-bit or higher. |
| **Fix**      | Re-save your images at a higher bit depth and re-upload.                                                  |