imgproxy/docs/watermark.md

Watermark

imgproxy supports the watermarking of processed images using another image.

Specifying watermark image

There are three ways to specify a watermark image using environment variables:

• IMGPROXY_WATERMARK_PATH: the path to the locally stored image
• IMGPROXY_WATERMARK_URL: the watermark image URL

• IMGPROXY_WATERMARK_DATA: Base64-encoded image data. You can easily calculate it with the following snippet:

  base64 tmp/watermark.webp | tr -d '\n'`.
  

You can also specify the base opacity of a watermark using IMGPROXY_WATERMARK_OPACITY.

📝 Note: If you're going to use the scale argument of watermark, it's highly recommended to use SVG, WebP or JPEG watermarks since these formats support scale-on-load.

Watermarking an image

Use the watermark processing option to put a watermark on a processed image:

watermark:%opacity:%position:%x_offset:%y_offset:%scale
wm:%opacity:%position:%x_offset:%y_offset:%scale

The available arguments are:

• opacity - watermark opacity modifier. The final opacity is calculated as base_opacity * opacity.
• position - (optional) specifies the position of the watermark. Available values:
  • ce: (default) center
  • no: north (top edge)
  • so: south (bottom edge)
  • ea: east (right edge)
  • we: west (left edge)
  • noea: north-east (top-right corner)
  • nowe: north-west (top-left corner)
  • soea: south-east (bottom-right corner)
  • sowe: south-west (bottom-left corner)
  • re: repeat and tile the watermark to fill the entire image
• x_offset, y_offset - (optional) specify watermark offset by X and Y axes. When using re position, these values define the spacing between the tiles.
• scale - (optional) a floating point number that defines the watermark size relative to the resulting image size. When set to 0 or omitted, the watermark size won't be changed.

Custom watermarks :id=custom-watermarks

You can use a custom watermark by specifying its URL with the watermark_url processing option:

watermark_url:%url
wmu:%url

The value of url should be the Base64-encoded URL of the custom watermark.

By default, imgproxy caches 256 custom watermarks with an adaptive replacement cache (ARC). You can change the cache size using the IMGPROXY_WATERMARKS_CACHE_SIZE environment variable. When IMGPROXY_WATERMARKS_CACHE_SIZE is set to 0, the cache is disabled.