subIm

subIm ( integer Input1, integer Input2, integer Output [, integer Mode =1])

Use this function to subtract one image from another on a pixel-by-pixel basis. The following formula is used for calculating the intensity of a target pixel:



If a pixel's result is negative, it will be clipped to zero or wrapped around depending on the Mode selected.

If the input images differ in types, they will be automatically converted to the type that forces conformity between the images. If the images or selections are different sizes, one or both of them will be clipped to match the minimal horizontal and vertical dimension of the images or selected regions of interests.

Parameters

Input1

An integer between 0 and 116 specifying the frame number of the first input image. A value of 0 represents the DMA memory buffer of the video device. Values in the range of 100-116 correspond to hidden frames.

Input2

An integer between 0 and 116 specifying the frame number of the second input image. A value of 0 represents the DMA memory buffer of the video device. Values in the range of 100-116 correspond to hidden frames.

Output

An integer between 1 and 116 specifying the output image frame number. Values in the range of 100-116 correspond to hidden frames.

Mode

An optional enumerated integer that describes the processing mode to use. Must be one of the following values:

M_WRAP=0 - pixel values in the output image that have negative values will be wrapped around the zero level.

M_CLIP=1 - pixel values in the output image that have negative values will be clipped to the zero value.

M_NORMALIZE=2 - pixel values in the output image to be linearly scaled to the full intensity range of the image.

Default: M_CLIP

Error flags

ERR_OK

The flag set if successful.

ERR_FAILED

The flag set if failed.

Example

This set of statements subtract one sample images from another and normalizes the result:

setCurDir("samples")

loadIm (1,"sample14.iwd")

loadIm (2,"sample15.iwd")

subIm (1,2,3,M_NORMALIZE)