Parametric edge detector has been reported to be successfully applied in actual coherent ladar intensity images corrupted by speckle. But there are isolated erroneous test points in the image processed by parametric test detector. By morphological filter, most isolated missing pixels in edge image background can be removed. Thus, the error of the edge detection can decrease exceedingly which is useful for subsequent image processing. Edge detection plays an important role in ladar image processing. Its capability has direct influence on precision and performance of ladar imaging system. Therefore it is necessary to evaluate the performance of a detector. In order to demonstrate the advantages of morphological filter based on parametric edge detection, the probability that an image pixel may be marked as an edge by this detector is calculated. This detector is applied to detect a large number of images degraded by speckle with different patterns and different carrier-noise-ratio. From the simulation results, the performance of morphological filter based on parametric edge detection is described.