Image functions

These functions operate on images, represented as matrices of RGB values (see PEN for more details).

Modify brightness

Modify contrast and brightness

Apply gamma correction to brightness

IMGRAYSCALE or IMGREYSCALE

Convert to grey scale

Replace one colour with another

Change size

Rotate

Horizontal flip

Vertical flip

Point-to-point warp

Shear in x direction

Shear in y direction

Median filter

Adjust saturation

Sharpen

Apply unsharp mask

Blur

Despeckle

Gaussian blur

Histogram equalization of individual colours

Histogram equalization of brightness

Histogram stretch of brightness

Histogram stretch of saturation

Histogram stretch of individual colours

Draw line

Draw ellipse

Draw text

Draw smooth text

Draw coloured rectangle

Emboss

Overlay images

Apply 3×3 convolution filter

Apply convolution filter

The functions are based on algorithms in the ImgSource library supplied by Smaller Animals Software, Inc. For more information, see http://www.smalleranimals.com/