F_VN_ScharrFilter
Calculates the first order derivative in x or y direction using a Scharr filter.
Syntax
Definition:
FUNCTION F_VN_ScharrFilter : HRESULT
VAR_INPUT
ipSrcImage : ITcVnImage;
ipDestImage : Reference To ITcVnImage;
eDestDepth : ETcVnElementType;
eFilterDirection : ETcVnFilterDirection;
hrPrev : HRESULT;
END_VAR
Inputs
|
Name |
Type |
Description |
|---|---|---|
|
ipSrcImage |
Source image | |
|
ipDestImage |
Reference To ITcVnImage |
Destination image (An appropriate destination image will be created if required.) |
|
eDestDepth |
Destination image depth | |
|
eFilterDirection |
Filter direction | |
|
hrPrev |
HRESULT indicating the result of previous operations (If SUCCEEDED(hrPrev) equals false, no operation is executed.) |
Return valueFurther information
The function F_VN_ScharrFilter applies a Scharr filter to the input image. The Scharr filter functions analogously to the Sobel Filter and differs from it only by the kernel.
Algorithm
The Scharr filter is closely related to the Sobel filter. However, it provides more accurate results than a 3 x 3 Sobel filter.
Parameter
Original image
The original image ipSrcImage can have any format.
Result image
The result image ipDestImage returns the filter result and has the same format as the original image ipSrcImage.
Result depth
The result depth eDestDepth defines which element type the result image ipDestImage has. A larger element type can display more information.
Filter direction
The filter direction eFilterDirection defines whether the Scharr filter is applied to the image in the X-direction (TCVN_FD_X) or in the Y-direction (TCVN_FD_Y).
Expert parameters
Further parameters can be found in the expert version F_VN_ScharrFilterExp.
Application
hr := F_VN_ScharrFilter(
ipSrcImage := ipImageIn,
ipDestImage := ipImageRes,
eDestDepth := TCVN_ET_USINT,
eFilterDirection:= TCVN_FD_X,
hrPrev := hr,
);
Original image | Result image |
|
|
Samples
Required License
TC3 Vision Base
System Requirements
Development environment | Target platform | PLC libraries to include |
|---|---|---|
TwinCAT V3.1.4024.54 or later | PC or CX (x64) with PL50, e.g. Intel 4-core Atom CPU | Tc3_Vision |