원문정보
초록
영어
Scanned topographic maps of cities may have uneven illumination and creases. They need to go through color dodging. Due to the unsatisfying result by homomorphic filter of Retinex theory and the low efficiency when color dodging, this paper proposes an improved color dodging for scanned topographic maps based on Retinal-cortex theory. The main idea is to introduce Fastest Fourier Transform In The West (FFTW) to get the illumination component of the image on the basis of homomorphic filter of the Retinal-cortex algorithm, and use homomorphic filter to get the reflectance component and get the final image by linear stretching treatment. Experiments have proved that this method keeps the details of the image while erasing the creases so that the brightness distribution is improved.
목차
1. Introduction
2. Retinex Theory and Single Scale Retinex Theory
2.1. Retinex Theory
2.2. Homomorphic filter based on SSR algorithm
3. Optimizing Homomorphic Filter Algorithm
3.1. Generation of Illumination Image
3.2. Stretching Method of the Result Image
4. Experiments and Analysis
4.1. The Effect of Color Dodging for the Whole Image
4.2. The Effect of Dodging for the Detail
4.3 Treatment of White Spot on the Image
4.4 Time Comparison between Homomorphic Filter and Improved Algorithm
5. Conclusions
Acknowledgements
References