An improved adaptive correction algorithm for non-uniform illumination panoramic image

An adaptive non-uniform illumination panoramic image enhancement algorithm was proposed, which can improve the visual effect of panoramic images captured under non-uniform illumination. Firstly, according to the illuminance-reflection imaging model, we adopt a bilateral filtering method to decompose the brightness into illuminance component and reflection component. Secondly, an adaptive gamma correction function is constructed, which can dynamically adjust the illuminance component. In the reflection component processing, an improved morphological operation is proposed to denoise and enhance the image details. Finally, we combine the illumination component with the reflection component to get the enhanced panoramic image. The experimental results show that the proposed algorithm can improve the effect of non-uniform illumination on the panoramic image, and can obtain better image contrast, detail information and visual effect

Low contrast detection factor based contrast enhancement and restoration for underwater images

7-13Marine ecosystem is the largest of earth’s aquatic ecosystems. It includes salt marshes, coral reefs, deep sea, sea floor, etc. To learn deep about the activities taking place inside, underwater imaging is a tool. But these images lack in contrast and brightness leading to the lack of information in the ocean activities. To enhance such low contrast underwater images, Low Contrast Detection Factor (LCDF) is proposed in this study. It uses the value, saturation and hue to enhance the low contrast regions and to restore the color. Quality assessment is done to substantiate the proposed algorithm. It is found that the entropy gives an average of 7.3. No-reference Quality Metrics such as Natural Image Quality Evaluator and Blind/ Referenceless Image Spatial Quality Evaluator shows an average value of 3.6 and 22.5, respectively. The blur metrics shows a value of 0.21. The quality metrics indicates that the naturalness of the underwater image is maintained while the contrast of the underwater image has increased