# Blurring

## Summary

This demonstration shows how to apply a filter to a part of an image and put the result back on the original.

• Crop Image Tool quickly extracts a rectangular portion of the input image. Cropping is done by dragging and dropping the Frame or Size parameter on top of the input image. You can choose the region of interest by resizing the yellow widget that appears on the image.
• Linear Filter Tool has a number of predefined filters. Here, a uniform (box) filter is used for blurring the image. You can change the amount of blurring by modifying the Filter Size parameter. You can also define your own filter by setting Filter Type to Custom.
• Join Images Tool can stitch up to eight images into a single image. If the images are taken from different positions (i.e. they have different frame/size settings), the tool recalculates the output image so that it appears to be coming from the camera connected to Image 0 input. In this example, the cropped and blurred part of the image (input Image 1) is overlaid on the original image (input Image 0).