> For the complete documentation index, see [llms.txt](https://docs.viesus.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.viesus.com/features/image-formats.md).

# Image Formats

VIESUS reads and writes the standard production image formats — JPEG, TIFF, PNG, BMP, WebP, and HEIC. RAW input is supported via an experimental loader.

## Supported formats

<table><thead><tr><th width="99">Format</th><th width="156.7999267578125">Read</th><th width="94">Write</th><th>Notes</th></tr></thead><tbody><tr><td><strong>JPEG</strong></td><td>✓</td><td>✓</td><td>Quality controlled via <code>JpegComprQuality</code> (1 – 100; default 95)</td></tr><tr><td><strong>TIFF</strong></td><td>✓</td><td>✓</td><td>Supports alpha channel; common for print production</td></tr><tr><td><strong>PNG</strong></td><td>✓</td><td>✓</td><td>Supports alpha channel — required for <a href="/pages/GqKSz0mDGOrFA8yfHtYa">Background Handling</a> modes 1 and 4</td></tr><tr><td><strong>BMP</strong></td><td>✓</td><td>✓</td><td>Uncompressed; useful for lossless intermediates</td></tr><tr><td><strong>WebP</strong></td><td>✓</td><td>✓</td><td>Modern web format with alpha support</td></tr><tr><td><strong>HEIC</strong></td><td>✓</td><td>✓</td><td>iPhone / modern mobile capture; carries HDR gainmaps used by <a href="/pages/JHPIX3efhL8sQDBhsChH">HDR Support</a></td></tr><tr><td><strong>RAW</strong></td><td>✓ (experimental)</td><td>—</td><td>Loaded via the experimental image loader (added in V10). Output is one of the above formats.</td></tr></tbody></table>

## Color modes

<table><thead><tr><th width="167.4000244140625">Color mode</th><th width="122.800048828125">Supported</th><th>Notes</th></tr></thead><tbody><tr><td>RGB</td><td>✓</td><td>Default working color space</td></tr><tr><td>CMYK</td><td>✓</td><td>Added in V7.50; useful for print pipelines</td></tr><tr><td>Grayscale</td><td>✓</td><td>Added in V7.50</td></tr><tr><td>RGBA (with alpha)</td><td>✓</td><td>Required for Background Handling modes 1 and 4; preserve as PNG, TIFF, or WebP — JPEG does not support alpha</td></tr></tbody></table>

## Key caveats

* **Alpha channel preservation** — save as PNG, TIFF, or WebP. JPEG and BMP drop alpha. See [Background Handling](/features/features/background-handling.md) for the modes that produce alpha output.
* **ICC profile handling** — embedded ICC profiles in input images are honored. Output profile behavior is controlled by [ICC Color Management](/features/features/icc-color-management.md).
* **HDR gainmaps** — HEIC inputs (and some JPEGs) can carry gainmaps that [HDR Support](/features/hdr-support.md) uses for SDR tonemapping.
* **DPI metadata** — JPEG, TIFF, PNG and WebP carry DPI metadata. The `DPIResolutionSaveMode` parameter controls how VIESUS handles it on write — see [Parameter Reference → Other](/configuration/parameter-reference/output-and-color.md#other-settings-other).
* **RAW loader** — experimental, format coverage varies by camera vendor. Verify your specific camera RAW format works before relying on it in production.

## Maximum dimensions and file size

| Limit                 | Value                                                                                              |
| --------------------- | -------------------------------------------------------------------------------------------------- |
| Max input dimensions  | No fixed library limit; constrained by available memory                                            |
| Max output dimensions | Same as input                                                                                      |
| Cloud API file size   | Images 20 KB – 50 MB; PDFs 20 KB – 1,000 MB. See [Cloud: Credits](/reference/cloud-api/credits.md) |


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