How to Crop Image without changing the aspect ratio

I need to crop an image without changing its aspect ratio. I am taking picture from CANON1100D using EDSDK. Captured image: Width = 1920 and Height=1280
Aspect ratio is 1.5. But I need picture which aspect ratio will be 1.33.


// convert into processing resolution (1600,1200) 

Image<Bgr, byte> runtime_frm = new Image<Bgr, byte>(frame.ToBitmap(1600,1200));

// also in bitmap processing 

// Bitmap a = new Bitmap(runtime_frm.ToBitmap());  
// Bitmap b = new Bitmap(a, new Size(1600,1200));

It's resizing the image, so the aspect ratio of image is changed, but it creates stress in image. I'd like to crop the image (1920x1280) to (1600x1200) in runtime.

How can I do this programmatically?

Solution

 public void Crop(Bitmap bm, int cropX, int cropY,int cropWidth,int cropHeight)
 {
       var rect = new System.Drawing.Rectangle(cropX,cropY,cropWidth,cropHeight);

       Bitmap newBm = bm.Clone(rect, bm.PixelFormat);

       newBm.Save("image2.jpg");
 }

Maybe something like that?

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