Figure 1.

Distinguishing cell images by thresholding. Images of the endoplasmic reticulum (a) and the microtubule cytoskeleton (b) are thresholded (a' and b') such that pixels with intensity in the range μ-30 to μ+30 are shown in white, where μ is the average pixel intensity of each image. Though images (a) and (b) are texturally and visually similar, images (a') and (b') are more distinguished. Image (a') contains more solid white regions, while (b') shows more interior speckling and feathering of edges.