Abstract: The underwater digital images generally suffer from blur, low contrast, non-uniform lighting, and diminished color. Digital image filtering in an important approach towards image enhancement. It involves the manipulation and interpretation of digital images. Images may get noisy due to various factors then filtering of images is become an important operation to de-noise the noisy images. Image sharpening must be performed to achieve it. This research paper proposed a preprocessing technique based on image to improve the quality of underwater digital images. We use Unsharp masking on l*a*b color s which sharpen the underwater digital image.
Keywords: Image enhancement, MIXED CLAHE, L*A*B color space, Unsharp masking, Pre-processing Underwater Image.