Fig. 6From: Acquisition of a single grid-based phase-contrast X-ray image using instantaneous frequency and noise filteringComparison of the magnified areas indicated by the blue boxes in Fig. 2 (RT3 and 6: caudal fin) for a, c absorption x-axis gradient and b, d phase-contrast X-ray images. Abs: absorption image; PCXI: phase-contrast X-ray image; IF: instantaneous frequency; dx: x-axis gradient image; RT: rectangleBack to article page