Figure 1From: Fast two-phase image segmentation based on diffusion equations and gray level setsThe level lines at different gray levels. (a) The noise image with Gaussian white noise of mean 0 and variance 0.2. (b) The smooth image by Gaussian low-pass filter with σ=1.5. (c)-(g) The level lines of the noise image at the gray level 60, 80, 120, 180, and 200. (h)-(l) The level lines of the smooth image at the gray level 60, 80, 120, 180, and 200.Back to article page