Most of imaging polarimeters in the field measure only a few components of the Mueller matrix or their combinations such as Stokes vector, degree of linear polarization (DOLP) and degree of circular polarization (DOCP). Our imaging polarimeter was similar in that it produced two combinations of 16 Mueller components. We upgraded our polarimeter to acquire the Mueller matrix of a scene in the field (Mueller image). Scenes consisted of flat plates mounted on a large panel, a large cylinder, and natural background such as trees and grass. We established a formula to derive Mueller images from the measurements with our instrument. Mueller images provided comprehensive information about the polarization effect on any targets in the scene, which were useful in distinguishing man-made objects from natural background. In addition, Mueller images enabled us to emulate some images by imaging polarimeters with limited capability. Comparison of those images with Mueller images provided an insight on the effectiveness and shortcomings of the associated imaging polarimeters.