Herror ::mod_parallels_xld (
Hobject Parallels,
Hobject Image,
Hobject *ModParallels,
Hobject *ExtParallels,
const HTuple &Quality,
const HTuple &MinGray,
const HTuple &MaxGray,
const HTuple &MaxStandard
)
HXLDModParaArray HXLDParaArray::ModParallelsXld (
const HImage &Image,
HXLDExtParaArray *ExtParallels,
const HTuple &Quality,
const HTuple &MinGray,
const HTuple &MaxGray,
const HTuple &MaxStandard
) const
Extract parallel XLD polygons enclosing a homogeneous area.
::mod_parallels_xld selects XLD parallels enclosing
homogeneous areas from the input parallels Parallels.
The parameter Image contains the corresponding gray value
image.
Only parallels having a quality factor larger than
Quality are examined. The algorithm performs parallel
cross sections one pixel apart, and parallel to the line segments in
the area of overlap between two parallel line segments.
In the first iteration, the mean gray value for each of the lines in
the cross section is calculated. In the second iteration, the
standard deviations of the gray values along each line are computed.
If the mean gray value of an area between parallels lies in the
interval [MinGray,MaxGray], and if the mean of
all standard deviations is smaller than the upper threshold
MaxStandard, the corresponding parallels are returned as
modified parallels in ModParallels.
In a second step, all polygon segments adjacent to parallels
bordering homogeneous areas are checked for homogeneity. To do so,
a rectangle having the witdth of the last area enclosed by a
modified parallel is constructed, and checked for homogeneity using
the algorithm described above. This process is continued as long as
there are adjacent polygon segments. The polygons thus found are
returned as extended parallels in ExtParallels.
Parameters
Parallels (input_object)
|
xld_para-array -> Hobject: HXLDParaArray
|
|
Input XLD parallels. |
Image (input_object)
|
image -> Hobject: HImage
|
|
Corresponding gray value image. |
ModParallels (output_object)
|
xld_mod_para-array -> Hobject * : HXLDModParaArray
|
|
Modified XLD parallels. |
ExtParallels (output_object)
|
xld_ext_para-array -> Hobject * : HXLDExtParaArray
|
|
Modified XLD parallels. |
Quality (input_control)
|
number -> HTuple.double / long
|
|
Minimum quality factor (measure of parallelism). |
|
Default value: 0.4 |
|
Suggested values: 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 |
|
Restriction: (0.0 <= Quality) && (Quality <= 1.0) |
MinGray (input_control)
|
integer -> HTuple.long
|
|
Minimum mean gray value. |
|
Default value: 160 |
|
Suggested values: 80, 100, 120, 140, 160, 180 |
|
Restriction: (0 <= MinGray) && (MinGray <= 255) |
MaxGray (input_control)
|
integer -> HTuple.long
|
|
Maximum mean gray value. |
|
Default value: 220 |
|
Suggested values: 140, 160, 180, 200, 220, 240 |
|
Restriction: ((0 <= MaxGray) && (MaxGray <= 255)) && (MaxGray >= MinGray) |
MaxStandard (input_control)
|
number -> HTuple.double / long
|
|
Maximum allowed standard deviation. |
|
Default value: 10.0 |
|
Suggested values: 5.0, 10.0, 15.0, 20.0 |
|
Restriction: MaxStandard >= 0.0 |
Possible Predecessors
::gen_parallels_xld
Possible Successors
::max_parallels_xld
See also
::info_parallels_xld
Module
Sub-pixel operators
Copyright © 1996-2002 MVTec Software GmbH