vitaly4uk / sorl-watermark

Image based watermarks for sorl-thumbnail

sorl-watermark

As of 12th July 2013, vbazhin will be taking over development and take care of implementing all the mentioned features. Everybody welcome him with a warm applause :D!

sorl-watermark offers drop-in engines for sorl-thumbnail, which automagically insert a specified image as watermark on top of the original thumbnail.

Of course everything is configurable, from watermark image to the position and the opacity.

If you are looking for a sorl engine to dynamically create text watermarks, you might want to have a look at zeus/watermark.

Note: This project uses Semantic Versioning as it's versioning scheme.

Setup

Install sorl-watermark, either by cloning from the github repository or by installing it via pip:

pip install sorl-watermark

Change sorl's thumbnail engine to the fitting one from sorl-watermark. By now PIL and pgmagick engines are implemented.

PIL:

THUMBNAIL_ENGINE = 'sorl_watermarker.engines.pil_engine.Engine'

Pgmagick:

THUMBNAIL_ENGINE = 'sorl_watermarker.engines.pgmagick_engine.Engine'

Next up you tell it which image should be used as a watermark. Note that this file has to live somewhere inside STATIC_ROOT.

THUMBNAIL_WATERMARK = 'my_watermark.png'

That's it for a simple setup. The engine will only apply the watermark if the thumbnail size is big enough.

See Advanced Usage for ways to dynamically change the watermark itself, it's size or ways to selectively apply watermarks.

Engines

sorl-watermark supports two of sorl-thumbnails backends:

• PIL (sorl_watermarker.engines.pil)
• GraphicsMagick (Magick++) via pgmagick (sorl_watermarker.engines.magick)

Advanced Usage

sorl-watermark also enhances the default thumbnail templatetag with some more options. (Well, actually it does not really enhance it, since the templatetag itself passes the options through to the engine itself by default)

By default, the templatetag syntax is:

{% thumbnail image key1=var1 key2=var2 %}

The following new options are available:

• watermark=imagefile This options takes an ImageFile and uses this one instead of the default watermark file, set via THUMBNAIL_WATERMARK
• watermark_size="x200" Changes the watermark's size. Takes the same options as the THUMBNAIL_WATERMARK_SIZE option.
• watermark_pos="north east" Specifies where the watermark shall be put. Accepts the same options as the THUMBNAIL_WATERMARK_POSITION setting.
• watermark_alpha=0.9 Sets the watermark's opacity. Has to be a value between 0 and 1.

Settings Reference

The following settings are available

• THUMBNAIL_WATERMARK Sets the image to be used as a watermark. The file must live within STATIC_ROOT.

• THUMBNAIL_WATERMARK_ALWAYS Stamp a watermark on every image. Default is True.

• THUMBNAIL_WATERMARK_SIZE Change the size of the watermark. This can either be a geometry string, as is usual with sorl-thumbnail ("x200", "200x200"), or a percentage. If given a percentage, the watermark will always be the given percentage of the thumbnail size.

• THUMBNAIL_WATERMARK_OPACITY An integer from 0 to 1, specifying the opacity of the watermark. Default is 0 (opaque).

• THUMBNAIL_WATERMARK_POSITION Specifies the position of the watermark. You can specify the position with a pair of padding values (in pixels) Ex. "20 20" will place watermark near the left-top corner, "-20 -20" - near the right-bottom corner. Either you can specify the position as:

  * "north"
  * "south"
  * "west"
  * "east"
  * "north east"
  * "south east"
  * "north west"
  * "south west"
  * "center"
  

  Default: "south east" (right-bottom corner)

  If you want to tile your image completely with a watermark, you should set:

  THUMBNAIL_WATERMARK_POSITION = 'tile'