[Paper] Smooth Gradation Reconstruction from False Contours in Quantized Natural Image

Akira Mizuno, Masayuki Ikebe
2015 ITE Transactions on Media Technology and Applications  
We propose a bit-depth expansion (BDE) method targeting natural images. In the analog part of an imaging system, signal intensity fluctuations occur due to noise (e.g. thermal noise in the image sensor). After that, in the digital part, the intensities are rounded off to limited levels. The latter process, which is quantization, increases the intensity of fluctuation errors caused by stochastic resonance. These errors are viewed as false contour artifacts in the gradation region. Our goal was
more » ... obtain the original signal from the quantized noisy signal. We formulated a probabilistic model based on this quantization process, and successfully reconstructed smooth gradations from noisy contours. Subjective evaluation by voting clarified that the output image has higher quality.
doi:10.3169/mta.3.251 fatcat:gla47wpwhbbbhprdpd7zwuze6m