SLANT Function (PV-WAVE Extreme Advantage)
Performs a Slant transform on a 2D square image. Images which are not already square, are zero-padded to have square dimensions before the transform is applied. Images whose dimensions are not a power of two are padded to have dimensions that are the nearest power of two.
Usage
result = SLANT(image[, direction])
Input Parameters
image—A 2D array.
direction—(optional) A parameter specifying the direction of the transform. (Default: –1)
– 1—The forward Slant transform is applied (default).1—The reverse Slant transform is applied.Returned Value
result—A 2D floating-point matrix with dimensions N-by-N, where N is the largest dimension of the input image rounded to the nearest larger power of two.
Keywords
None.
Discussion
The Slant transform uses sawtooth shaped basis functions, sk(z), which are defined recursively from the 2-by-2 basis. The equations for the Slant transform matrix generation are found in Gonzalez and Woods, p. 147.
The Slant Transform is then applied as:
T = S*image*S
where S is the Slant transform matrix and T is the transform result.
Example
; Read an image.
image = IMAGE_READ(!IP_Data + 'airplane.tif')
; Compute the Slant transform.
slant_image = SLANT(image('pixels')); Display the transformed image.
TVSCL, IPALOG(slant_image)
See Also
