Speckle filtering method of ultrasonic cardio-image based on mathematical morphology

During the ultrasonic cardio-image 3-D reconstruction, one of the difficult problems is that there are some speckles that show strongly variance of image gray level. the speckles reduce the space difference and remain the detailed structure under cover. The filtering technology can be classified into space domain filtering and frequency domain filtering. and spatial filtering methods have been widely used in ultrasonic medical image processing. according to the statistical characteristic of the speckle. the speckle filtering method based on multidirectional morphological structure is presented. The experiment shows that the speckle noise has been filtered and image details have been preserved by the method based on local statistical property of the image. certainly the speckle filtering is not the final objective and would like to be proved and perfected in the further research of ultrasonic image segmentation and analyzing.