Operations and properties on a picture (photo)

Blur

Blurs an image

Gaussian Blur

Blurs an entire image to a stronger degree

Colorize

Adjusts the hue and saturation of the colors in an image

Crosshatch

Adds a crosshatched effect to an image

Despeckle

Removes noise from an image or selection

Edge-detect

Creates a tracing of an image

Emboss

Adds a grayscale relief effect to an image

Negative

Reverses the colors in an image to make a negative

Oil painting

Makes an image look like a painting

Pencil drawing

Creates a pencil drawing from an image

Sepia

Adds a sepia color to an image to make it look like an old photograph

Sharpen

Increases the color difference in adjacent pixels in an image to create a sharper image