Operators

plane_deviation (Operator)

Name

plane_deviation — Calculate the deviation of the gray values from the approximating image plane.

Signature

plane_deviation(Regions, Image : : : Deviation)

Description

The operator plane_deviation calculates the deviation of the gray values in Image from the approximation of the gray values through a plane. Contrary to the standard deviation in case of intensity slanted gray value planes also receive the value zero. The gray value plane is calculated according to gen_image_gray_ramp.

If F is the plane, alpha, beta, mean are the parameters of the image
plane and (r',c') is the center, Deviation is defined by:

Deviation = sqrt(sum(((alpha*(r-r')+beta*(c-c')+mean)-Image(r,c))^2)/F) .

Attention

Note that the operator plane_deviation only considers the given Regions and ignores any previously set domain of the input image Image. It should be noted that the calculation of Deviation does not follow the usual definition. It is defined to return the value 0.0 for an image with only one pixel.

Parallelization

• Multithreading type: reentrant (runs in parallel with non-exclusive operators).
• Automatically parallelized on tuple level.

Parameters

Regions (input_object)  region(-array) object

Regions, of which the plane deviation is to be calculated.

Image (input_object)  singlechannelimage object (byte / cyclic)

Gray value image.

Deviation (output_control)  real(-array) (real)

Deviation of the gray values within a region.

Complexity

If F is the area of the region the runtime complexity amounts to O(F).

Result

The operator plane_deviation returns the value 2 (H_MSG_TRUE) if Image is of the type 'byte'. The behavior in case of empty input (no input images available) is set via the operator set_system(::'no_object_result',<Result>:), the behavior in case of empty region is set via set_system(::'empty_region_result',<Result>:). If necessary an exception is raised.