CImage:Expand

The Expand method enlarges the background "canvas"around the image. The border is assigned a value and Gaussian random noise may be optionally added. The result replaces the current image.

Syntax

    CRect describes the new image size and placement. See Remarks.

    value is the pixel value of the new background, and may be a number or string.

    noise is the optional noise sigma, and may be a number or string.

    On success, this method returns true.

    On failure, this method returns false.

Remarks

This method creates a new, larger image that extends the borders with a value and optional random noise. The scale of the image is not changed, but the existing image is imbedded into a larger canvas. The new size and the position of the current image are encoded in the members of a CRect as follows:

    Let xmax = new column dimension, in pixels.

    Let ymax = new row dimension, in pixels.

    Let xmin = column (x) position in the expanded image.

    Let ymin = row (y) position in the expanded image.

    Use CRect:Set( xmin, xmax, ymin, ymax ) or an equivalent method to initialize the CRect.

If you do not want to add random noise to the border region, set noise=0 or omit the value from the argument list.

Example

Suppose that a CImage I exists. The following script fragment doubles its width and height and centers the current image in the new image. The new background value is 1000 and the noise sigma is 8.25:

Related Topics

CImage, CRect