Integrated NIR-HE based SPOT-5 image enhancement method for features preservation and edge detection

Recently, many researchers have directed their attention to methods of predicting shorelines by the use of multispectral images. Thus, a simple and optimised method using image enhancements is proposed to improve the low contrast of the SPOT-5 images in the detection of shorelines. In order to correct the surface reflectance in a SPOT-5 image, a false colour composite has been used, which is more favourable in the detection of vegetation and water bodies. Therefore, it can prevent misclassified pixels of the shoreline. The NIR channel is important in this study to ensure the contrast of the vegetated area and sea classification, due to the high reflectance of leaves in the near infrared wavelength region. This study used five scenes of interest to show the different results in shoreline detection. The results demonstrated that the proposed method performed in an enhanced manner as compare to current methods when dealing with the low contrast ratio of SPOT-5 images. As a result, by utilising the Near-Infrared Histogram Equalization (NIR-HE) method, the contrast of all datasets was efficiently restored, producing a higher efficiency in edge detection, and achieving higher overall accuracy. The false colour composite is used to ensure that land and water are identified by utilising the NIR channel. The improved filtering method showed significantly better shoreline detection results than the other filter methods, and it was concluded that this method would be useful for detecting and monitoring the shoreline edge in Tanjung Piai.