You can successfully decode & read all the EAN-8 barcodes in the gif image file called ean8-barcode by using following VB.NET class code.
Dim datas() AsString = BarcodeReader.read("c:/ean8-barcode.gif", BarcodeReader.EAN8)
How to Customize EAN-8 Barcode Scanning Rate in VB.NET Applications
Read & Recognize Large-Size EAN-8 Barcode Using VB.NET Class Code
When you are reading certain maximum EAN-8 barcode from an image file, you can largely reducing the scanning time by activating the property of "maxOneBarcodePerPage".
If you set "maxOneBarcodePerPage" to true, it will stop reading & decoding after it detects the EAN-8 barcode. Otherwise, it will use five algorithms to read this image file and each algorithm will decode the image file from four directions.
Read & Decode EAN-8 Barcode by Scanning Partial Image File in VB.NET Project
When you are scanning an EAN-8 barcode which is only a small part of the target image file, then you can let the VB.NET EAN-8 barcode decoder scan & read EAN-8 barcode in that small area.
For example, the EAN-8 barcode is located in the top 20% and bottom 20% area of target image file, you can direct the VB.NET barcode decoding dll to scan EAN-8 barcode just in that area. And following VB.NET class code can help you achieve that:
Dim setting As OptimizeSetting = New OptimizeSetting()
setMaxOneBarcodePerPage(True)
Dim top20 As ScanArea = New ScanArea(New Drawing.PointF(0.0F, 0.0F), New Drawing.PointF(100.0F, 20.0F))
Dim bottom20 As ScanArea = New ScanArea(New Drawing.PointF(0.0F, 80.0F), New Drawing.PointF(100.0F, 100.0F))
Dim areas As List(Of ScanArea) = New List(Of ScanArea) areas.Add(top20) areas.Add(bottom20)
setting.setAreas(areas)
Dim datas() AsString = BarcodeReader.read("c:/ ean8-barcode.gif", BarcodeReader.EAN8, setting)
Note: This VB.NET EAN-8 barcode scanning component set the default value of the most left top point as (0%, 0%) and that of the most right bottom point as (100%, 100%).