Based on the analysis above, IDGB is calculated like
IDGB = [n.summation over (i=1)] [w.sub.1](i) x [w.sub.2](i)/[n.summation over (i=1)] [w.sub.2](i), (5)
One hundred and sixty actual infrared target images are used to evaluate the validity of metrics IDGB and SDLB.
7(d), it could be concluded that IDGB and SDLB are both validity for the quality evaluation of infrared target image and could give an accurate measurement of interference to target detection.
We use twenty-four sets of actual infrared images to compare the performance of proposed metrics IDGB and SDLB with the traditional metrics, and each set is consisted of 3 to 5 images which have different backgrounds but the same target.
The proposed metrics IDGB and SDLB show that the image with the best quality is Fig.
In order to compare the performances of the proposed metrics IDGB and SDLB with the traditional metrics when evaluating the infrared images which have the same background but different targets, we add targets T1, T2 and T3, and synthesis three images shown in Fig.
IDGB and SDLB could also give the right order of image quality.