Fig. 2. Scanner estimation of length of two wires (1.190 mm diameter, 0.95 m long; and 0.229 mm diameter, 1.12 m long) and hair (0.057 mm diameter and approx. 3 m long) with and without image sharpening. Images are from scans at 17 different resolutions. Scanner setting: Color photograph, high-resolution printer output, saved as tiff files. Adjustments: original = no image adjustment; sharpened = image sharpened with Photoshop. See text for parameters.