How to Define Barcode Crop Region for Faster Read

by Hairil Hasyimi Bin Omar

One of the most important feature in IronBarcode is the ability for the users to specify Crop Regions. The aim of this feature is to enable IronBarcode to only read specific barcodes or area specified by the Crop Region in the image by using IronSoftware.Drawing.Rectangle object. Using this feature will not only reduce error in reading, but also improve the reading performance.

Install with NuGet

Install-Package BarCode

nuget.org/packages/BarCode/

or

Download DLL

Download DLL

Manually install into your project

Find Crop Region coordinates and size in an image

There are many ways available for users to find the coordinates of a point in an image. One of it is to load the image using 'Paint' application in the computer. To get the first coordinate of the Crop Region, move the cursor to prefered first spot which will be the top left corner of the Rectangle and take the x,y coordinate given by the app at the bottom left of the screen. Then, locate the second point which will be the bottom right corner of the Rectangle. Refer to the image below for clearer understanding.

Setting CropRegion reference

The coordinate values can then be used as properties for the Rectangle object. The width of the object can be defined as x2 - x1 while height can be defined as y2 - y1.

:path=/static-assets/barcode/content-code-examples/how-to/set-crop-region-instantiate-CropRegion.cs

using IronBarCode;

int x1 = 62;
int y1 = 29;
int x2 = 345;
int y2 = 522;

IronSoftware.Drawing.Rectangle crop1 = new IronSoftware.Drawing.Rectangle(x: x1, y: y1, width: x2-x1, height: y2-y1);

Imports IronBarCode

Private x1 As Integer = 62
Private y1 As Integer = 29
Private x2 As Integer = 345
Private y2 As Integer = 522

Private crop1 As New IronSoftware.Drawing.Rectangle(x:= x1, y:= y1, width:= x2-x1, height:= y2-y1)

Apply CropRegion and Read Barcode

Once we have done the hard work of defining the CropRegions where we want IronBarcode to read, we can then apply the object into BarcodeReaderOptions as one of the properties besides other settings as well, which can then be used as a parameter in the BarcodeReader.Read() method. The code snippet below shows

:path=/static-assets/barcode/content-code-examples/how-to/set-crop-region-apply-CropRegion.cs

using IronBarCode;
using System;

int x1 = 62;
int y1 = 29;
int x2 = 345;
int y2 = 522;

IronSoftware.Drawing.Rectangle crop1 = new IronSoftware.Drawing.Rectangle(x: x1, y: y1, width: x2 - x1, height: y2 - y1);

BarcodeReaderOptions options = new BarcodeReaderOptions()
{
    CropArea = crop1
};

var result = BarcodeReader.Read("sample.png", options);
foreach (var item in result)
{
    Console.WriteLine(item.Value);
}

Imports IronBarCode
Imports System

Private x1 As Integer = 62
Private y1 As Integer = 29
Private x2 As Integer = 345
Private y2 As Integer = 522

Private crop1 As New IronSoftware.Drawing.Rectangle(x:= x1, y:= y1, width:= x2 - x1, height:= y2 - y1)

Private options As New BarcodeReaderOptions() With {.CropArea = crop1}

Private result = BarcodeReader.Read("sample.png", options)
For Each item In result
	Console.WriteLine(item.Value)
Next item

From the code snippet above, we used the instantiated Rectangle in BarcodeReaderOptions object as the CropArea property. We then use this BarcodeReaderOptions object as a parameter in the BarcodeReader.Read() method to apply the CropArea in the image and read the barcodes inside.