You can do length measurements on the following pages:
This page proposes a simple and accurate method to report reproducible length measurements, on the Shroud of Turin, based on digital images. Essentially, a reported measurement includes its endpoints as rectangular coordinates (a.k.a. x and y points). The technique is rather trivial but it is necessary in cases where a good degree of precision is needed.
This method becomes useful since a reported length (height) or width of an "image body part" cannot be objectively verified: almost all such images have no definite borders. For example, one can report a face width of 15cm, but it is elusive where that measurement was done. It is very difficult to verify these basic claims without further objective data. At the very least, the endpoints of these measurements should be provided.
For the following, I am referring to the full digital Shroud image publicly distributed by the Arcidiocesi di Torino, after the summer 2002 restoration. This image was taken from http://www.sindone.org/it/scient/restauro_gallery.htm and is copyrighted Arcidiocesi di Torino (The URL of this image was http://www.sindone.org/restauro/hires/sindone_recto.jpg). The image has 613px (pixel) in width and 2286px in length. By convention, the upper left corner has coordinates (0,0); consequently, the lower right corner has coordinates (612,2285).
Measurements taken by Bruno Barberis and Gian Maria Zaccone give (frontal image at the bottom left, dorsal image at the top) 441.5 cm for the right height, and 442.5 cm for the left height. The bottom width is 113.0 cm and the top width is 113.7 cm.
Note: when the photo was taken, the Shroud was being extended by its four corners.
This image has been calibrated: one pixel is appr. 1.985 mm. This calibration is explained in the following paragraph. Essentially, the width of the Shroud is 568 px; so 1 px = 1130/568 mm.
The Shroud left upper corner is at (15,21), the left lower corner is at (19,2266), the right lower corner is at (594,2273) and its right upper corner is at (594,18). Even these four measurements are approximated to +- 1px due to the fuzziness of the Shroud borders on the image. Needless to say, the Shroud is not perfectly rectangular as for example the upper edge is concave; near its center it goes to (x,27) for x around 270. To measure the length (a.k.a. height) and width of the Shroud, endpoint locations must be assumed. For the length, points (270,27) and (270,2263) are used, that is its length is 2237 px. For the width, points (32,1116) and (599,1116) are used, that is its width is 568px. Assuming that the Shroud width is 1130 mm, one horizontal pixel is 1130/568 mm, that is 1.989 mm +- 0.01mm according to the +-1px approximation. Assuming that the Shroud length is 4425 mm, one vertical pixel is 4425/2237 mm, that is 1.978 mm. Assuming that the image is indeed symmetrical, we may use the calibration of 1 px = 1.985 mm with an error of less than 0.01mm.
Note: the author does not know the exact endpoints used to measure the length of 4425 mm and width of 1130 mm. But if these values are exact, it can be verified that the calibration can be from 1.975mm to 1.995 mm per pixel taking any perpendicular endpoints.
A measurement can be done by using your favorite graphic software. (For example Gimp, free and available for different flavors of Unix and Windows.) Usually you would download the image and by using the "compass tool" (a.k.a. rule tool) measure the number of pixels between two points. For a vertical and horizontal measurement, the length is the number of pixels multiplied by the calibration. Or you can use the previous links to do online measurements.
For instance, a measurement of the width of the "entire face" (face encompassing the hair on both sides) could be from (260, 1299) to (367, 1299); that is 108 horizontal pixels. Therefore, the width is 108*1.985 mm = 21.4 cm (rounded). This measurement is still disputable, but at least stating the endpoints makes it reproducible.
Note: measurements of body parts on the image does not necessarily translate as measurements on a purported real body draped by the Shroud: the image could have been created while the cloth draped the body, creating some wraparound distortions, or the Shroud could have stretched since the image was formed, etc.
Some other examples of measurements: The height of the frontal body image from (311, 1224) to (311, 2256) is 1032 pixels, that is 1032*1.985 mm = 2.05 m. (We certainly cannot conclude that this is the height of the Man of the Shroud as this measurement does not take into account many other factors.) The empty space from (320,1132) to (320,1224) gives 18.3 cm. The back body image from (320,81) to (320,1132) gives 2.09 m. Actually, all these endpoints are disputable: the contour of the image is not very clear, in particular near the feet.
The Secundo Pia's digital photo was sent to me by Prof. Giulio Fanti. The Enrie's photo was taken from Ray Schneider's web page which was rescaled by him to 613 pixels in width.