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AVL.LogarithmImage(AvlNet.Image, AvlNet.Region, float?, float, bool, AvlNet.Image, AvlNet.Profile)

Computes a natural logarithm of each pixel.

Namespace:	AvlNet
Assembly:	AVL.NET.dll

Syntax


public static void LogarithmImage(
	AvlNet.Image inImage,
	AvlNet.Region inRoi,
	float? inScale,
	float inOffset,
	bool inNormalizeZero,
	out AvlNet.Image outImage,
	out AvlNet.Profile diagLutProfile
)

Parameters

inImage: Type: AvlNet.Image
Input image
inRoi: Type: AvlNet.Region
Region of interest, or null.
inScale: Type: System.Nullable<System.Single>
Scaling factor (default: 255), or null.
inOffset: Type: System.Single
Offset factor
inNormalizeZero: Type: System.Boolean
Specifies whether the output range should be rescaled to start from 0
outImage: Type: AvlNet.Image
Output image
diagLutProfile: Type: AvlNet.Profile
Profile depicting the resulting look-up table of the logarithm transform

Description

The operation applies logarithmic operator to each pixel of an image. Logarithmic operator is defined as follows:

\[inScale \cdot \frac{log(inOffset + |P(x,y)|)}{log(inOffset + M)}\]
where:

M is the maximum of the inImage type (i.e. 255 for UInt8, 127 for Int8).
inScale is the expected maximum value of the transformation. If set to Auto it will result in value 127 for Int8 image and 255 for other image types.
inOffset value corresponds to the camera's black level. Its default value is equal 1 and causes the strongest possible transform.

When inNormalizeZero is set to True, the result is not only scaled, but also normalized so that pixel value 0 is still transformed into value 0. This assures that the entire output value range is utilized.

Examples

The LogarithmImage performed on the sample image with parameters inScale = 250, inOffset = 50. The middle image inNormalizeZero = False and the left image has inNormalizeZero = True.

Hardware Acceleration

This operation supports automatic parallelization for multicore and multiprocessor systems.