CImage:ScalePolyVal

The ScalePolyVal method applies a 1-D polynomial function of pixel value. The polynomial is independent of image coordinate.

Syntax

bResult = CImage:ScalePolyVal( CPolynomial )

The CPolynomial is the set of polynomial coefficients.

On success, this method returns true.

On failure, this method returns false.

Remarks

This method applies a polynomial function of pixel value, independent of position in the image. One application of this method is in applying a linearity correction.

When applying this method to by the pixel type, Mira handles value overflow by truncating the output pixel value at the limits for the pixel type. For example, applying this method to a short type image may result in pixel values outside the range [-32768, 32767]. Although Mira automatically truncates the result to this range, you may need to retain the values that fall outside the pixel type limits. To avoid the truncation, you may wish to call SetPixelType to promote the current image to a "larger" pixel type, such as long or float, before performing the ScalePolyVal operation.

Example

Assume that a CPolynomial P contains coefficients that correct non-linear signal response in the image. The following script loads an image from files sPath, applies the linearity correction, and displays the result:

I = new_image()	-- create a new CImage
I:Open( sPath )	-- load the image
if I:GetPixelType() <= 3 then	-- if byte, short, or ushort
I:SetPixelType("float")	-- convert I to 32 bit float type
end
I:ScalePolyVal( P )	-- perform the operation on image I
I:Display()
I:delete()

Syntax

Remarks

Example

Related Topics