Riemann-Liouville Fractional Differential Enhancement Method of Digital Image

To solve some problems on image enhancement, such as losing details and falling into a sub or over enhancement, a method of image enhancement based on fractional differentiation algorithm is proposed.According to the basic fractional differentiation form and auto-correlation of digital image, the situation is improved that the differentiation of a constant is not zero with the commonly accepted Riemann-Liouville definition of fractional differentiation.The method is used to define the coefficients of differentiation enhancement template.Then, a fractional differential convolution template is constructed in 8directions.Experimental results show that the proposed method can greatly increase high frequency, effectively improve the low frequency, strengthen the textural detail of image and improve the mean value, definition and comentropy of image quality index.The enhanced images have better visual quality.