
Denoising 135
denoising with F = ROF [330] we obtain, with our proposed framework (i.e.
by applying TV denoising to the curvature), a denoised image result with
PSNR=47.85, whereas direct TV denoising on the image yields PSNR=46.77.
The influence of homogeneous regions on the PSNR is discussed next.
FIGURE 5.15: Left: test image. Right: PSNR values of image, curvature
and normal along contour.
FIGURE 5.16: Left: test image. Right: PSNR values of image, curvature
and normal along contour.
5.6.2.4 PSNR in homogeneous regions
On homogeneous or slowly varying regions, (5.4) is no longer valid and we
have instead
|∇a| |∇n|, (5.26)
so now
κ(I) ' κ(n) + ∇ · (