MimDistance()函数

Synopsis

Perform a distance transformation.

Format

void MimDistance(SrcImageBufId, DestImageBufId, DistanceTransform)

Description

This function determines the shortest distance between each blob’s pixel and its edges, and assigns this distance to the pixel. It produces a type of contour mapping of a blob.

The SrcImageBufId parameter specifies the identifier of the source of the operation. This parameter must be given an image buffer identifier.

The DestImageBufId parameter specifies the identifier of the destination of the resulting image. This parameter must be given an image buffer identifier.

The DistanceTransform parameter specifies the way in which the minimum distance from blob pixel to blob edge is calculated. This parameter must be set to M_CHAMFER_3_4, which approximates the true distance from blob pixel to blob edge using a 3 x 3 neighborhood algorithm.

The M_CHAMFER_3_4 transform requires that the destination buffer be large enough to hold a number at least three times the maximum distance from a blob pixel to its edge. For example, an 8-bit buffer (255 max) can be used for a maximum distance of 85 pixels and a 16-bit buffer (65535 max) for a maximum distance of 21845 pixels.

Note

This function is optimized for packed binary buffers.

Status

In-place processing is supported, but the source and destination image buffers cannot partially overlap (a situation that can only occur when using child buffers).