A simple quantitative image processing system for pulsed soft x rays with time and spatial resolution is described. The system consists of easily obtained commercial components including a microchannel plate-phosphor screen combination, a charge coupled device camera, an image memory board, and a personal computer. To make a quantitative measurement possible, the image processing is used in conjunction with measurement of the ''phosphor screen current.'' Performance of the system is examined using a soft x-ray source generated with a plasma focus device. The order of intensity, similar to 10(12) photons/s mm(2) mrad(2) 0.01% BW of Ar K lines is observed for about 20 ns from the pinched plasma in which 3% of Ar is added to the 6 Torr H-2.