ByteScout Barcode Reader SDK – VBScript – Barcode Image Preprocessing Filters

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ByteScout Barcode Reader SDK – VBScript – Barcode Image Preprocessing Filters

printable version:
ByteScout-BarCode-Reader-SDK-VBScript-Barcode-Image-Preprocessing-Filters.pdf

barcode image preprocessing filters in VBScript and ByteScout BarCode Reader SDK

How To: tutorial on barcode image preprocessing filters in VBScript

Today you are going to learn how to barcode image preprocessing filters in VBScript. ByteScout BarCode Reader SDK helps with barcode image preprocessing filters in VBScript. ByteScout BarCode Reader SDK is the SDK for barcode decoding. Can read all popular types from Code 128, GS1, UPC and Code 39 to QR Code, Datamatrix, PDF417. Images, pdf, TIF images and live web camera are supported as input. Designed to handle documents with noise and defects. Includes optional splitter and merger for pdf and tiff based on barcodes. Batch mode is optimized for high performance with multiple threads. Decoded values can be exported to XML, JSON, CSV or into custom data format.

VBScript, code samples for VBScript, developers help to speed up the application development and writing a code when using ByteScout BarCode Reader SDK. This VBScript sample code should be copied and pasted into your application’s code editor. Then just compile and run it to see how it works. Code testing will allow the function to be tested and work properly with your data.

Trial version can be downloaded from our website. Source code samples for VBScript and documentation are included.

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TestBarcodeReading.vbs

      ' This exmaple demonstrates the use of image filters to improve the decoding or speed.

Dim result

Set reader = CreateObject("Bytescout.BarCodeReader.Reader")
reader.RegistrationName = "demo"
reader.RegistrationKey = "demo"

' Set barcode type to find
reader.BarcodeTypesToFind.Code128 = True


' WORKING WITH LOW CONTRAST BARCODE IMAGES

' Add the contrast adjustment for the low contrast image
reader.ImagePreprocessingFilters.AddContrast(40)

result = result & "Image ""low-contrast-barcode.png""" & vbCRLF

reader.ReadFromFile "low-contrast-barcode.png"

If reader.FoundCount = 0 Then
	result = result & "No barcode found!" & vbCRLF
Else
	For i = 0 To reader.FoundCount - 1
        result = result & "Found barcode with type " & CStr(reader.GetFoundBarcodeType(i)) & " and value """ & reader.GetFoundBarcodeValue(i) & """" & vbCRLF
    Next
End If

reader.ImagePreprocessingFilters.Clear()
result = result & vbCRLF


' WORKING WITH NOISY BARCODE IMAGES

' Add the median filter to lower the noise
reader.ImagePreprocessingFilters.AddMedian()

result = result & "Image ""noisy-barcode.png""" & vbCRLF

reader.ReadFromFile "noisy-barcode.png"

If reader.FoundCount = 0 Then
	result = result & "No barcode found!" & vbCRLF
Else
	For i = 0 To reader.FoundCount - 1
        result = result & "Found barcode with type " & CStr(reader.GetFoundBarcodeType(i)) & " and value """ & reader.GetFoundBarcodeValue(i) & """" & vbCRLF
    Next
End If

reader.ImagePreprocessingFilters.Clear()
result = result & vbCRLF


' WORKING WITH DENSE AND ILLEGIBLE BARCODES

' Add the scale filter to enlarge the barcode to make gaps between bars more distinguishable
reader.ImagePreprocessingFilters.AddScale_2(2) ' enlarge twice

result = result & "Image ""too-dense-barcode.png""" & vbCRLF

reader.ReadFromFile "too-dense-barcode.png"

If reader.FoundCount = 0 Then
	result = result & "No barcode found!" & vbCRLF
Else
	For i = 0 To reader.FoundCount - 1
        result = result & "Found barcode with type " & CStr(reader.GetFoundBarcodeType(i)) & " and value """ & reader.GetFoundBarcodeValue(i) & """" & vbCRLF
    Next
End If

reader.ImagePreprocessingFilters.Clear()
result = result & vbCRLF


' REMOVE EMPTY MARGINS FROM IMAGE TO SPEED UP THE PROCESSING

' Add the crop filter to cut off empty margins from the image.
' This will not improve the recognition quality but may speed up the processing 
' if you enabled multiple barcode types to search. 
reader.ImagePreprocessingFilters.AddCropDark()

result = result & "Image ""barcode-with-large-margins.png""" & vbCRLF

reader.ReadFromFile "barcode-with-large-margins.png"

If reader.FoundCount = 0 Then
	result = result & "No barcode found!" & vbCRLF
Else
	For i = 0 To reader.FoundCount - 1
        result = result & "Found barcode with type " & CStr(reader.GetFoundBarcodeType(i)) & " and value """ & reader.GetFoundBarcodeValue(i) & """" & vbCRLF
    Next
End If

reader.ImagePreprocessingFilters.Clear()
result = result & vbCRLF


Msgbox result


Set reader = Nothing