Do you have a blurry image that you would like to sharpen? Most image editing applications provide an image sharpen function. If you don't already have an image editing application, you can either pay over $100 for Adobe Photoshop, or you can download the free Paint.NET image editing application for Windows.
Image sharpening works scanning through the pixels of the image and performing a mathematical matrix operation on each pixel. The formula uses the color and intensity of the pixel, along with the color and intensity of the surrounding pixels to calculate how much to increase the contrast of the target pixel.
Adjusting the amount of sharpening sets amount to adjust the contrast, and the size of the area of surrounding pixels to use in the calculation.
Be aware that too much sharpening can increase the amount of noise in the image.
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