Abstract: The image acquired by the remote sensing camera will appear to be a certain fuzzy
phenomenon after transmitted it to the ground. It will get high quality image after restoration, and it is
necessary to use some methods to assess the quality of recovery image. This paper proposes a sharpness
assessment for remote sensing image, which picks up gradient from images, calculates the number of
the pixels on the region of maximum gradient and the data is used as sharpness parameter. We get the
upgrade rate after comparing the sharpness parameters between the fuzzy image and the recovered
image. We demonstrate the validity of this new method through some experiments. The experimental
results show that the method can accurately assess the sharpness upgrade rate of the restored image, and
get better results in the inhibiting effect of weak ringing ripples and the anti-noise performance when
the signal noise ratio over 22 dB.

Key words: image quality assessment, image resolution, remote sensing image, gradient, signal noise
ratio