Question

我的目标是使用VB.net创建一个Windows窗体应用程序从图像中读取条形码（现在形成一个文件，稍后用网络摄像头拍摄）并将文本写入文本框。我已经找到了很多关于如何使用Zxing库解码条形码的例子，几乎除了vb.net之外的所有语言。我有一个包含代码39（我相信）条形码的图像。

添加对Zxing.dll的引用并导入所需的命名空间后，我有这个：

Imports ZXing.OneD
Public Class Form2
    Private webcam As WebCam
    Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        webcam = New WebCam()
        webcam.InitializeWebCam(imgVideo)
        webcam.Start()
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        imgCapture.Image = imgVideo.Image 'I plan to use this later


        Dim reader As New ZXing.OneD.Code39Reader
        Dim image1 As Bitmap
        image1 = Image.FromFile("C:\Capture.jpg") 'this is the image I'm using for testing purposes

        reader.decode(image1)
    End Sub
End Class

行reader.decode(image1)生成错误：

"Error  1   Value of type 'System.Drawing.Bitmap' cannot be converted to 'ZXing.BinaryBitmap'"

显然，我正在处理我还不了解的事情......所以我乞求帮助！我使用的是Visual Studio 2010 Express。

我又一次改变了它。此代码不会生成任何错误，但它不返回任何内容。

Imports ZXing
Imports ZXing.OneD
Public Class Form2
    Private webcam As WebCam
    Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        webcam = New WebCam()
        webcam.InitializeWebCam(imgVideo)
        webcam.Start()
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        imgCapture.Image = imgVideo.Image 'I plan to use this later

        Dim reader As Code39Reader = New Code39Reader
        Dim image1 As Bitmap = New Bitmap("C:\Capture.bmp")
        Dim bitmapBytes As Byte()
        Using stream As New System.IO.MemoryStream
            image1.Save(stream, image1.RawFormat)
            bitmapBytes = stream.GetBuffer
        End Using
        Dim Lumin As LuminanceSource = New RGBLuminanceSource(bitmapBytes, image1.Width, image1.Height, bitmapFormat:=RGBLuminanceSource.BitmapFormat.RGB24)

        Dim HBin As Common.HybridBinarizer = New Common.HybridBinarizer(Lumin)
        Dim Bitm As BinaryBitmap = New BinaryBitmap(HBin)
        Dim res As String = reader.decode(Bitm).Text
    End Sub
End Class

修改* 这是可行的解决方案。谢谢你的帮助！

Imports ZXing
Imports ZXing.OneD
Imports System.IO
Public Class Form2
    Private webcam As WebCam
    Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        webcam = New WebCam()
        webcam.InitializeWebCam(imgVideo)
        webcam.Start()
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        imgCapture.Image = imgVideo.Image 'I plan to use this later
        Dim reader As New ZXing.BarcodeReader
        Dim image1 As Bitmap
        image1 = Image.FromFile("C:\Capture.bmp")
        Dim res As Result = reader.Decode(image1)
        MsgBox(res.Text)
    End Sub

    Public Function GetRGBValues(ByVal Bmp As Bitmap) As Byte()
        Dim Rect As New Rectangle(0, 0, bmp.Width, bmp.Height)
        Dim BmpData As System.Drawing.Imaging.BitmapData = Bmp.LockBits(Rect, System.Drawing.Imaging.ImageLockMode.ReadOnly, Bmp.PixelFormat)
        Dim Ptr As IntPtr = BmpData.Scan0
        Dim Bytes As Integer = BmpData.Stride * Bmp.Height
        Dim RgbValues As Byte() = New Byte(Bytes - 1) {}
        System.Runtime.InteropServices.Marshal.Copy(Ptr, RgbValues, 0, Bytes)
        Bmp.UnlockBits(BmpData)
        Return RgbValues
    End Function
End Class

Answer 1

因此RGBLuminanceSource需要一个字节数组的构造函数。

我似乎无法为此找到合适的文档，但这会将Image转换为Bytes的数组：

Public Function ImageToByteArray(ByVal Img As Image) As Byte()
    Using ms As New MemoryStream
        Img.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg)
        Return ms.ToArray()
    End Using
End Function

示例电话：

Dim Lumin As New ZXing.RGBLuminanceSource(ImageToByteArray(image1), image1.Width, image1.Height)

如果上述方法不起作用，那么这个功能只会拍摄图像的像素（我不确定上面的内容是否超过像素）：

Public Function GetRGBValues(ByVal Bmp As Bitmap) As Byte()
    Dim Rect As New Rectangle(0, 0, bmp.Width, bmp.Height)
    Dim BmpData As System.Drawing.Imaging.BitmapData = Bmp.LockBits(Rect, System.Drawing.Imaging.ImageLockMode.ReadOnly, Bmp.PixelFormat)

    Dim Ptr As IntPtr = BmpData.Scan0

    Dim Bytes As Integer = BmpData.Stride * Bmp.Height
    Dim RgbValues As Byte() = New Byte(Bytes - 1) {}

    System.Runtime.InteropServices.Marshal.Copy(Ptr, RgbValues, 0, Bytes)
    Bmp.UnlockBits(BmpData)

    Return RgbValues
End Function

Answer 2

您的问题在于您尝试阅读的条形码。不是你如何尝试阅读它们。您需要在code 39上开始和停止字符。在要渲染条形码的每个字符串的开头和结尾添加一个星号*。没有这些字符，您的条形码无效，无法读取。

用vb.net读取代码39条形码

2 个答案: