CImCombine:Rank

CImCombine:Rank

The Rank method merges the pixel values using the rank percentile statistic at each location.

Syntax

CImage = CImCombine:Rank( CImageSet, percentile )

CImageSet contains the collection of images to be combined.
percentile is the rank % value to be computed.
CImage is a new image created by this method.
On success, this method returns a new CImage.
On failure, this method returns nil.

Remarks

Each pixel in the output image is the rank percentile value of pixels at the same location in all the images of the CImageSet. The percentile is specified in the range of 0 to 100. The median is the special case of rank = 50%.

Example

Suppose a CImageSet named S exists. The following script fragment combines the images by the Rank method after normalizing their luminance by the median statistic computed inside the central 10% of the image:

C = CImCombine:new()	-- create a CImCombine object
R = CRect:new(10,50,10,50)	-- central 10% of the image
C:SetRelRect( R )	-- specify CImage and CRect to measure
C:SetNormStat("median")	-- use the median as the normalization statistic
C:SetNormMethod("scale")	-- scale to normalize the image set
pctile = 45	-- set the 45th percentile rank
I = C:Rank( S, pctile )	-- combine the image set and return a new image
I:Display()	-- show the new image
C:delete()	-- when done with S, remove it from memory