如何设置分辨率并调整捕获图像的大小? [英] how to set resolution and resize the captured image?

问题描述

嗨！全部，
我已经在VB.Net中创建了一个图像捕获代码，为此我使用了interop.WIA.dll，
我面临的问题是，当我捕获图像时，它的大小很大，我想将其分辨率和大小调整为较小.
以下是我用来捕获图像的代码，我无法调整图像的大小.

Hi! all,
I have created a image capturing code in VB.Net, for this i used the interop.WIA.dll,
the problem i am facing is when i capture the image, it''s size is big and i want to resize it''s resolution and size to small.
Following is the code i''m using to capture the image and i can''t resize the image.

Private Sub btnGrab_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGrab.Click
        Dim item As WIA.Item
        Try
            'executes the device's TakePicture command
            item = SelectedDevice.ExecuteCommand(WIA.CommandID.wiaCommandTakePicture)
        Catch ex As System.Exception
            MessageBox.Show("Problem Taking Picture. Please make sure that the camera is plugged in and is not in use by another application. " & vbCrLf & "Extra Info:" & ex.Message, "Problem Grabbing Picture", MessageBoxButtons.OK, MessageBoxIcon.Warning, MessageBoxDefaultButton.Button1, MessageBoxOptions.DefaultDesktopOnly)
            Exit Sub
        End Try
        Dim jpegGuid As String
        'retrieves jpegKey from registry, used in saving JPEG
        Dim jpegKey As Microsoft.Win32.RegistryKey = Microsoft.Win32.Registry.ClassesRoot.OpenSubKey("CLSID\{D2923B86-15F1-46FF-A19A-DE825F919576}\SupportedExtension\.jpg")
        jpegGuid = CType(jpegKey.GetValue("FormatGUID"), String)
        'loops through available formats for the captured item, looking for the JPG format
        For Each format As String In item.Formats
            If (format = jpegGuid) Then
                'transfers image to an imagefile object
                Dim imagefile As WIA.ImageFile = CType(item.Transfer(format), WIA.ImageFile)
                Dim Counter As Integer 'counter in loop appended to filename
                Dim LoopAgain As Boolean = True
                Dim height As Int32 = CInt(Val(10))
                Dim width As Int32 = CInt(Val(10))

                'searches directory, gets next available picture name
                Do Until LoopAgain = False
                    Dim Filename As String = SavePath & "\" & txtPrefix.Text & Counter.ToString & ".jpg"
                    'if file doesnt exist, save the file
                    If Not System.IO.File.Exists(Filename) Then
                        SavedFilePath = Filename
                        imagefile.SaveFile(Filename) 'saves file to disk
                        lblCapName.Text = FormatPath(Filename)
                        lblImageName.Text = txtPrefix.Text & Counter.ToString & ".jpg"
                        picCap.Image = Image.FromFile(Filename) 'loads captured file to picturebox
                        Image.FromFile(Filename)
                        'Image()
                        LoopAgain = False
                        imagefile.Height.ToString()
                    End If
                    Counter = Counter + 1
                Loop
            End If
        Next
        If grpSaved.Enabled = False Then
            grpSaved.Enabled = True
        End If
    End Sub

推荐答案

希望使用VB.NET调整图像大小并裁剪图像 [

Hope Image Cropping with Image Resizing Using VB.NET[^] article from CP might help you.

此处是调整图像大小的便捷小程序

Here is a handy little routine for resizing images

private static Image resizeImage(Image imgToResize, Size sizeOfNewImage)
        {
            Bitmap bmp = new Bitmap(sizeOfNewImage.Width, sizeOfNewImage.Height);
            Graphics gra = Graphics.FromImage((Image)bmp);
            gra.InterpolationMode = InterpolationMode.HighQualityBicubic;//Can try various other quality enumerations
            gra.DrawImage(imgToResize, 0, 0, sizeOfNewImage.Width, sizeOfNewImage.Height);
            gra.Dispose();
            return (Image)bmp;
        }

希望对您有帮助

Hope this helps

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