F_VN_ReadBarcode
Detect and interpret a 1d barcode within the provided image. Can be canceled by Watchdog.
Syntax
Definition:
FUNCTION F_VN_ReadBarcode : HRESULT
VAR_INPUT
ipSrcImage : ITcVnImage;
ipDecodedData : Reference To ITcVnContainer;
eBarcodeType : UDINT;
hrPrev : HRESULT;
END_VAR
Inputs
|
Name |
Type |
Description |
|---|---|---|
|
ipSrcImage |
Source image (USINT elements, 1 channel or 3 channel (3 channel input is expected to be RGB and internally converted to Gray)) | |
|
ipDecodedData |
Reference To ITcVnContainer |
Returns the decoded code (ContainerType_Vector_String_SINT) |
|
eBarcodeType |
UDINT |
Types of barcode to search for (ETcVnBarcodeType) |
|
hrPrev |
HRESULT indicating the result of previous operations (If SUCCEEDED(hrPrev) equals false, no operation is executed.) |
Return valueFurther information
The function F_VN_ReadBarcode detects a barcode in the image and reads it.
Algorithm
The function first searches for horizontally aligned codes and then for vertically aligned codes in the image.
Parameter
Input image
The input image ipSrcImage must be a 1-channel or 3-channel image with the element type USINT (8-bit). 3-channel images will be interpreted as RGB and converted internally into grayscale images.
Read data
The data read from the code are returned as a string in the container ipDecodedData. The container is of the type ContainerType_Vector_String_SINT.
Barcode type
The parameter eBarcodeType defines the barcode types to be searched for in the image. All barcode types in the enum ETcVnBarcodeType are supported. It is possible to select more than one type. It is recommended to restrict the selection to the types actually occurring in the end application in order to improve the runtime.
eBarcodeType := TCVN_BT_EAN13 + TCVN_BT_CODE128;
Use TCVN_BT_ANY to search for all available barcode types.
Expert parameters
The expert version F_VN_ReadBarcodeExp contains additional parameters.
Read data from container
If the code was successfully found and decoded, the code content is returned in the container ipDecodedData and can be exported to a string using the function F_VN_ExportSubContainer_String.
hr := F_VN_ExportSubContainer_String( ipDecodedData, 0, sText, nMaxLength, hr);
Required License
TC3 Vision Code Reading
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 |