Abstract: A method for obtaining quantitative data which relates the sound pressure distribution in a body to an ultrasound pulse waveform which propagates through the body, based on photoelastic measurement and analysis. The method involves producing a first image of the body, into which the ultrasound pulse was launched, by recording the image of linearly polarized straboscopic light which is directed into the body. Thereafter, a second image is taken of the stroboscopic light with the principal axis of the linear polarizer offset by 45.degree. relative to the first image. The first and second images are combined to produce a synthesized image and the above-mentioned quantitative data is derived from the synthesized image.