gray_projections

gray_projections ( Region, Image : : Mode : HorProjection, VertProjection )

Calculate horizontal and vertical gray-value projections.

gray_projections calculates the horizontal and vertical gray-value projections, i.e., the mean values in the horizontal and vertical direction of the gray values of the input image Image within the input region Region.

If Mode = 'simple' is selected the projection is performed in the direction of the coordinate axes of the image, i.e.:

                                      ----
                                      \
    HorProjection(r)  =  1/n(r+r')    /    Image(r+r',c+c')
                                      ----
                                   (r+r',c+c') in Region

                                      ----
                                      \
    VertProjection(c) =  1/n(c+c')    /    Image(r+r',c+c')
                                      ----
                                   (r+r',c+c') in Region

Here, (r',c') denotes the upper left corner of the smallest enclosing axis-parallel rectangle of the input region (see smallest_rectangle1), and n(x) denotes the number of region points in the corresponding row r+r' or column c+c'. Hence, the horizontal projection returns a one-dimensional function that reflects the vertical gray value changes. Likewise, the vertical projection returns a function that reflects the horizontal gray value changes.

If Mode = 'rectangle'is selected the projection is performed in the direction of the major axes of the smallest enclosing rectangle of arbitrary orientation of the input region (see smallest_rectangle2). Here, the horizontal projection direction corresponds to the larger axis, while the vertical direction corresponds to the smaller axis. In this mode, all gray values within the smallest enclosing rectangle of arbitrary orientation of the input region are used to compute the projections.

Parameters

`Region` (input_object)	region `->` object
Region to be processed.

`Image` (input_object)	image `->` object : byte / int2 / uint2
Grayvalues for projections.

`Mode` (input_control)	string `->` string
Method to compute the projections.
Default value: 'simple'
List of values: 'simple', 'rectangle'

`HorProjection` (output_control)	real-array `->` real
Horizontal projection.

`VertProjection` (output_control)	real-array `->` real
Vertical projection.

Parallelization Information

gray_projections is reentrant and processed without parallelization.

Module

1D Metrology