Title :
CCD noise removal in digital images
Author :
Faraji, Hilda ; MacLean, W. James
Author_Institution :
Dept. of Electr. & Comput. Eng., Toronto Univ., Ont.
Abstract :
In this work, we propose a denoising scheme to restore images degraded by CCD noise. The CCD noise model, measured in the space of incident light values (light space), is a combination of signal-independent and signal-dependent noise terms. This model becomes more complex in image brightness space (normal camera output) due to the nonlinearity of the camera response function that transforms incoming data from light space to image space. We develop two adaptive restoration techniques, both accounting for this nonlinearity. One operates in light space, where the relationship between the incident light and light space values is linear, while the second method uses the transformed noise model to operate in image space. Both techniques apply multiple adaptive filters and merge their outputs to give the final restored image. Experimental results suggest that light space denoising is more efficient, since it enables the design of a simpler filter implementation. Results are given for real images with synthetic noise added, and for images with real noise
Keywords :
CCD image sensors; adaptive filters; brightness; image denoising; image restoration; CCD noise removal; adaptive restoration technique; camera response function; digital images; image brightness space; image restoration; incident light values; light space denoising; multiple adaptive filters; normal camera output; signal-dependent noise term; signal-independent noise term; Brightness; Cameras; Charge coupled devices; Degradation; Digital images; Extraterrestrial measurements; Image restoration; Noise measurement; Noise reduction; Signal restoration; Camera response function (CRF); lightspace; noise modeling; nonlinear filtering and enhancement; restoration;
Journal_Title :
Image Processing, IEEE Transactions on
DOI :
10.1109/TIP.2006.877363