PERBAIKAN KUALITAS DENGAN CLAHE DAN SEGMENTASI OTOMATIS DENGAN WATERSHED TRANSFORMATION PADA CITRA BAWAH AIR; IMAGE ENHANCEMENT WITH CLAHE AND AUTOMATIC SEGMENTATION USING WATERSHED TRANSFORMATION ON UNDERWATER IMAGE

Indrayanti, Lathifah R, Agus Harjoko

2015 | Disertasi | FMIPA

Underwater image has been used as object in a variety of activities such as underwater archeology, underwater habitat mapping, environmental monitoring, underwater objects search, seabed mapping and so forth. Underwater image acquired by unmanned underwater camera generally has a low contrast, uneven lighting and bluish color. One of the factors that affect recognition results in pattern recognition is the quality of the input image. Imagery acquired from the source does not always have good quality. In this research, image quality improvements with CLAHE and segmentation by watershed transformation.The result of improvements measured with mean and energy as measuring instrument for each color channel. Experiments conducted with variety of clip limit ratio to determine the results of image enhancement. Best result of iamge enhancement occured when 0.05 clip limit ratio is used in which produce 49,96% improvement in R channel and 80,25% improvement in G channel. Segmentation is conducted using watershed transformation preceded by opening and closing operations to reduce over-segmentation. Image segmentation results of images that went through enhancement process are compared to segmentation results of original images. Test result shows that segmentation result accuracy of images that went through enhancement are higher than segmentation result accuracy of original images.

Kata Kunci : mage Enhancement; automatic segmentation; CLAHE; watershed transformation; underwater image.