Figure 13: Images containing horizontally oriented wavelet distortions generated by adding random values to (a) or via actual quantization of (b) the LH subbands of a five-level DWT of the image lena. In both images, the contrasts of the distortions have been proportioned according to the contrast-matching proportions as described in Section 5.2. Both images contain distortions at a total RMS contrast of approximately 0.18. These images were created assuming sRGB display characteristics and are meant to be viewed from approximately four picture heights.