Cover picture: Automatic detection of cardiac Ca²⁺ sparks: intermediate steps of the detection algorithm. (A) Normalized line scan confocal images of spontaneous Ca²⁺ sparks. (B) Binary image for regions above (1, red) or below (0, black) m + 2. (C) Binary image at level of m + Cri (Cri = 3.8). Detected spark events are marked by boxes in B. (D) Detected events and fluorescence image. See the article by Cheng et al. on p. 606.