tshirt- Transforms an image to place it in a region of a tshirt image
tileimage - Tiles an image to a given size with various tile arrangements.
shadows - Applies drop shadows to an image.
grid - Superimposes a set of horizontal and/or vertical grid lines on an image.
lupe - Applies a magnifying glass effect in a local area of an image.
multicrop - Crops and unrotates multiple images from a scanned image.
peelingpaint - Applies a peeling paint effect to an image.
picframe - Adds a picture frame around an image.
picturefold - Applies a map-like folded appearance to an image.
PINBARREL - Corrects or applies pincushion and/or barrel lens distortion to an image.
PUZZLE - Applies a puzzle like effect to an image.
RANDOMCLIPART - Randomly distributes clip art over the image.
From a comment on HN:
SKETCH - Applies a sketch effect to an image. SMARTCROP - Automatically crops an image to a given size around the hightest detail region.
TILER - Converts an image into a tilable texture.
UNPERSPECTIVE - Automatically removes pespective distortion from an image.
UNROTATE - Automatically unrotates a rotated image and trims the surrounding border.
VINTAGE1 - Applies a a classic vintage effect to an image
DIAGCOLLAGE - Collages three images in a diagonal orientation.
DEFISHEYE - Corrects for fisheye distortion in an image.
EMBROIDERY - Applies an embroidery effect to each color in an image.
DOMINANTCOLOR - Computes the dominant color in an image.
OVERLAPCROP - Creates a sequence of cropped subsections permitting optional overlap of the subsections.
TRIMMER - Trims the background from any number of specified sides of an image.
outfit - use texture image onto image of clothing
splitcrop - split one image into many pieces
whiteboard - Processes a picture of a whiteboard to clean up the background and correct the perspective
postagestamp - convert image into stamp
glow - add glow effect