This article explains how .NET developers can crop an EMF image inside their .NET applications. Image cropping usually refers to the removal of the outer parts of an image to help improve the framing. Cropping may also be used to cut out some portion of an image to increase the focus on a particular area.

Aspose.Imaging for .Net API supports two different approaches for cropping images: by shifts and by rectangles. The EmfImage class provides an overloaded version of the Crop method that accepts 4 integer values denoting left, right, top, and bottom. Based on these four values, the Crop method moves the image boundaries toward the center of the image while discarding the outer portion. The EmfImage class provides another overloaded version of the Crop method that accepts an instance of the Rectangle class. You can cut out any portion of an image by providing the desired boundaries to the Rectangle object.

Cropping by Shifts

In C#:

//[C# Code Sample]
// create an instance of Rasterization options
EmfRasterizationOptions emfRasterizationOptions = new EmfRasterizationOptions();
emfRasterizationOptions.BackgroundColor = Aspose.Imaging.Color.WhiteSmoke;

// create an instance of PNG options
PdfOptions pdfOptions = new PdfOptions();
pdfOptions.VectorRasterizationOptions = emfRasterizationOptions;

//Declare variables to store file paths for input and output images
string filePath = @"TestEmfBezier.emf";
string outPath = filePath + ".pdf";

//Load an existing image into an instance of EMF class
using (Aspose.Imaging.FileFormats.Emf.EmfImage image = (Aspose.Imaging.FileFormats.Emf.EmfImage)Aspose.Imaging.Image.Load(filePath))
{
  using (FileStream outputStream = new FileStream(outPath, FileMode.Create))
  {
    //Based on the shift values, apply the cropping on image
    //Crop method will shift the image bounds toward the center of image
    image.Crop(30, 40, 50, 60);

    // Set height and width
    pdfOptions.VectorRasterizationOptions.PageWidth = image.Width;
    pdfOptions.VectorRasterizationOptions.PageHeight = image.Height;

    //Save the results to disk
    image.Save(outputStream, pdfOptions);
  }
}

Or, in VB.NET:

//[VB.NET Code Sample]

' create an instance of Rasterization options
Dim emfRasterizationOptions As New EmfRasterizationOptions()
emfRasterizationOptions.BackgroundColor = Aspose.Imaging.Color.WhiteSmoke

' create an instance of PNG options
Dim pdfOptions As New PdfOptions()
pdfOptions.VectorRasterizationOptions = emfRasterizationOptions

'Declare variables to store file paths for input and output images
Dim filePath As String = "TestEmfBezier.emf"
Dim outPath As String = filePath & Convert.ToString(".pdf")

'Load an existing image into an instance of EMF class
Using image As Aspose.Imaging.FileFormats.Emf.EmfImage = DirectCast(Aspose.Imaging.Image.Load(filePath), Aspose.Imaging.FileFormats.Emf.EmfImage)
      Using outputStream As New FileStream(outPath, FileMode.Create)
            'Based on the shift values, apply the cropping on image
            'Crop method will shift the image bounds toward the center of image
            image.Crop(30, 40, 50, 60)

            ' Set height and width
            pdfOptions.VectorRasterizationOptions.PageWidth = image.Width
            pdfOptions.VectorRasterizationOptions.PageHeight = image.Height

            'Save the results to disk
            image.Save(outputStream, pdfOptions)
      End Using
End Using

Cropping by Rectangle

In C#:

//[C# Code Sample]

// create an instance of Rasterization options
EmfRasterizationOptions emfRasterizationOptions = new EmfRasterizationOptions();
emfRasterizationOptions.BackgroundColor = Aspose.Imaging.Color.WhiteSmoke;

// create an instance of PNG options
PdfOptions pdfOptions = new PdfOptions();
pdfOptions.VectorRasterizationOptions = emfRasterizationOptions;

//Declare variables to store file paths for input and output images
string filePath = @"TestEmfExtPen.emf";
string outPath = filePath + ".pdf";

//Load an existing image into an instance of EMF class
using (Aspose.Imaging.FileFormats.Emf.EmfImage image = (Aspose.Imaging.FileFormats.Emf.EmfImage)Aspose.Imaging.Image.Load(filePath))
{
    using (FileStream outputStream = new FileStream(outPath, FileMode.Create))
    {
        //Create an instance of Rectangle class with desired size
        //Perform the crop operation on object of Rectangle class
        image.Crop(new Aspose.Imaging.Rectangle(30, 50, 100, 150));

        // Set height and width
        pdfOptions.VectorRasterizationOptions.PageWidth = image.Width;
        pdfOptions.VectorRasterizationOptions.PageHeight = image.Height;

        //Save the results to disk
        image.Save(outputStream, pdfOptions);
    }
}

Or, in VB.NET:

//[VB.NET Code Sample]

' create an instance of Rasterization options
Dim emfRasterizationOptions As New EmfRasterizationOptions()
emfRasterizationOptions.BackgroundColor = Aspose.Imaging.Color.WhiteSmoke

' create an instance of PNG options
Dim pdfOptions As New PdfOptions()
pdfOptions.VectorRasterizationOptions = emfRasterizationOptions

'Declare variables to store file paths for input and output images
Dim filePath As String = "TestEmfExtPen.emf"
Dim outPath As String = filePath & Convert.ToString(".pdf")

'Load an existing image into an instance of EMF class
Using image As Aspose.Imaging.FileFormats.Emf.EmfImage = DirectCast(Aspose.Imaging.Image.Load(filePath), Aspose.Imaging.FileFormats.Emf.EmfImage)
      Using outputStream As New FileStream(outPath, FileMode.Create)
            'Create an instance of Rectangle class with desired size
            'Perform the crop operation on object of Rectangle class
            image.Crop(New Aspose.Imaging.Rectangle(30, 50, 100, 150))

            ' Set height and width
            pdfOptions.VectorRasterizationOptions.PageWidth = image.Width
            pdfOptions.VectorRasterizationOptions.PageHeight = image.Height

            'Save the results to disk
            image.Save(outputStream, pdfOptions)
      End Using
End Using

Overview: Aspose.Imaging for .NET

Aspose.Imaging for .NET is an image processing & manipulation component that allows developers to create, edit, draw, or convert images in their .NET application. It allows developers to convert image files to PSD, BMP, JPEG, PNG, TIFF, and GIF formats. Moreover, a set of pens, brushes, and fonts can be used to draw images or add new elements and text to existing images. Aspose.Imaging for .NET works well with both web and windows applications. Also, it provides support for the Silverlight platform.