Research On Digital X-ray Medical Image Enhancement Methods Based On Multiscales

During developing computed radiography, we find degradation of digital X-ray medical image such as low contrast and blurring, which are caused by complexity of body tissue, effects of X-ray scattering and electrical noise etc., and can worsen the results of analysis and diagnosis. So it is necessary to enhance X-ray medical image to improve its visual quality, including contrast enhancement and detail enhancement.The paper gives a review of some existing enhancement methods for medical images, and points out the limitations of these methods based on single-scale in frequency domain and space domain. In this paper, the existing enhancement methods of digital X-ray medical image are improved for different body part, and image processing methods based on multi-scales in frequency domain and space domain are presented. The content of the paper are summarized up as follows:Based on the characteristics of chest X-ray images, the enhancement algorithm based on multi-scales in frequency domain is presented, whish employs different enhancement to different region in chest. The result shows that the algorithm can efficiently enhance the detailed information in lighter region of images and be also suitable for enhancement of darker region of images. It overcomes the over enhancement of darker region of chest images.Based on multi-scales and histogram equalization technology, an adaptive contrast/edge enhancement method is presented. The algorithm uses adaptive histogram equalization to process the approximate coefficients of images, while enhancing the detail coefficients of images. The method can improve the visibility of the multi-scales edge information of image and the contrast of total image. The technique gets over, so that the ordinary methods based on multi-scales only can enhance the multi-scales edge information of image.In order to increase image visual quality of digital X-rays, this article describes retinex model based human visual system. A multi-scales retinex technique in space domain is used for anatomically enhancing digital radiograph. Experiments show that MSR can efficiently realize dynamic range compression and more observably improve contrast of digital X-rays than other techniques. We find that though some of these techniques work well for some images, our technique is better at exploiting the hidden area of digital radiograph.While doing research on computed radiography, we suggest that DSP image processing card based on the PCI bus be used to realize sampling of image data,...