ETcVnBorderInterpolationMethod
Offers methods to extrapolate values of non-existing pixels. On the one hand, this is used for filtering functions to enable filtering at the image borders (where the filter mask reaches over the border). On the other hand, this is used to extrapolate the undefined pixels after a geometric image transformation.
Syntax
Definition:
TYPE ETcVnBorderInterpolationMethod :
(
TCVN_BIM_CONSTANT := 0,
TCVN_BIM_REPLICATE := 1,
TCVN_BIM_REFLECT := 2,
TCVN_BIM_WRAP := 3,
TCVN_BIM_REFLECT_101 := 4,
TCVN_BIM_DEFAULT := 4,
TCVN_BIM_TRANSPARENT := 5,
TCVN_BIM_ISOLATED_CONSTANT := 16,
TCVN_BIM_ISOLATED_REPLICATE := 17,
TCVN_BIM_ISOLATED_REFLECT := 18,
TCVN_BIM_ISOLATED_WRAP := 19,
TCVN_BIM_ISOLATED_REFLECT_101 := 20
)DINT;
END_TYPE
Values
|
Name |
Description |
|---|---|
|
TCVN_BIM_CONSTANT |
iiiiiii | abcdefgh | iiiiiii (with some specified i) |
|
TCVN_BIM_REPLICATE |
aaaaaaa | abcdefgh | hhhhhhh |
|
TCVN_BIM_REFLECT |
gfedcba | abcdefgh | hgfedcb |
|
TCVN_BIM_WRAP |
bcdefgh | abcdefgh | abcdefg |
|
TCVN_BIM_REFLECT_101 |
hgfedcb | abcdefgh | gfedcba |
|
TCVN_BIM_DEFAULT |
Choose this if you don't know which method to select (same as REFLECT_101). |
|
TCVN_BIM_TRANSPARENT |
Corresponding pixels in the destination image will not be modified. Only available for geometric image transformations. |
|
TCVN_BIM_ISOLATED_CONSTANT |
Similar to CONSTANT, but ROIs are handled as isolated, which means surrounding image pixels outside the ROI are ignored. |
|
TCVN_BIM_ISOLATED_REPLICATE |
Similar to REPLICATE, but ROIs are handled as isolated, which means surrounding image pixels outside the ROI are ignored. |
|
TCVN_BIM_ISOLATED_REFLECT |
Similar to REFLECT, but ROIs are handled as isolated, which means surrounding image pixels outside the ROI are ignored. |
|
TCVN_BIM_ISOLATED_WRAP |
Similar to WRAP, but ROIs are handled as isolated, which means surrounding image pixels outside the ROI are ignored. |
|
TCVN_BIM_ISOLATED_REFLECT_101 |
Similar to REFLECT_101, but ROIs are handled as isolated, which means surrounding image pixels outside the ROI are ignored. |
Further information
Border interpolation is used to simulate pixel values outside of the image. This is necessary, for example, when applying a filter or a morphological operator to an image. For example, if a filter iterates over the image, it must be specified how the filter behaves at the image edges where parts of the filter kernel lie outside of the image. For this purpose the non-existent pixels outside of the image are simulated so that the filter operation can still be performed. The method with which this simulation is performed is defined with the enum ETcVnBorderInterpolationMethod. The value TCVN_BIM_REFLECT is often a good choice; it reflects the outer image pixels with the image border as a mirror plane.