Use Edge Enhancement for the Dead Pixel Correction

[kausthubhak]

In the current implementation, if the first pixel is bad, we wouldn't know that since we started testing the middle pixel of the next line. So, it's better to use edge enhancement techniques to include the first pixel in checking whether it's bad or not.

[marianadeem-10xe]

Yes, the current implementation assumes that all the neighboring pixels are good pixels and requires improvement. The case in which there are more than one bad pixel in a 3x3 window is not currently handled. However, the implementation does include a gradient based check to prevent edge blurring during DPC.

The first pixel is tested using reflective padding on the image.