ImageFX allows you to add filters to your WordPress images uploaded through the normal media uploader.

For more information:
http://ottopress.com/2011/customizing-wordpress-images-with-a-plugin-imagefx/

Example:
http://demo.wpsmiththemes.com/minfolio/all-image-styles-example/

Default filters:

Greyscale with except Blue, Red, Green
Sepia tone with 6 alternatives
Colorize with red, yellow, green, blue, purple
Photonegative
Emboss & Emboss Edge
Brighten (50, 100)
Gaussian Blur & Selective Blur
Mean Removal
Smooth
Negative
Contrast Negative and Positive
Rounded Corners

ImageFX is expandable and retractable, so removing and adding other filters using your own customized image manipulation functions is easy.
Register new filters with:

Individually: imagefx_register_filter( ‘filter_name’, ‘cb_function’); //Note: cb_function defaults to imagefx_filter_{filter_name}
Bulk: imagefx_register_filters( array( ‘filter_name’, ‘filter_name’ ) );

Unregister existing filters with:

Individually: imagefx_unregister_filter( ‘filter_name’ );
Collectively: imagefx_unregister_filters( array( ‘filter_name’, ‘filter_name’) );
Specifically: imagefx_unregister_colorize_filters(); & imagefx_unregister_greyscale_filters(); & imagefx_unregister_sepia_filters(); imagefx_unregister_rounded_filters();

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