Processing And Analysis Of X-ray Real-time Image Based On High-resolution CCD Camera

With the cost of high-resolution, high-performance digital video camera coming down, an x-ray real-time imaging system was comprised by the group based on high-resolution digital camera and the new generation of image intensifier, which have the advantages of high spatial resolution and better anti-interference, compared with the system consisting of traditional image intensifier and ordinary analog video CCD camera. The paper was mainly to develop detection software, which contained image acquisition and processing functions, it can realize the calculation of characteristic parameters, but also be able to assist evaluation staff to determine the level of defects.First of all, the hardware structure of the imaging system was introduced in the paper. After being familiar with the CCD digital camera and acquisition card, the image acquisition and preservation software was compiled, and then according to the request of x-ray detection and the actual needs of auto aluminum wheels detection, a suite of software was developed. In the image pre-processing part, by analyzing the image noise, the multi-frame superposition and median filtering method were respectively used to achieve the expected results. For the low contrast, gray-scale transformation, histogram equalization and other methods were adopted to enhance the image. Aiming at the characteristics of x-ray aluminum wheels image and the shortage of conventional image enhancement features, a new enhancement algorithm based on Curve let transform was presented, then the contrast and the quality of the original images were improved, and the better visual effects of the minutia area was achieved. In the image segmentation stage, the subtraction technique was introduced, and got a nice result, but in the segmentation process, it was likely to cause distortion defects. Then based on the analysis of the traditional edge detection algorithm, a combination algorithm of edge detection algorithm based on the SUSAN operator and target area was proposed, and achieved the desired result. Finally, on the basis of the testing requirement and casting defects level standard, defect classification, characteristics of expression and presentation methods were introduced, and then the perimeter, area and non-geometrical characteristics were measured. Furthermore, a real-time display system was designed, so that defect features were real-time displayed. In addition, the scanning function was also designed and a row or column of the gray value can be displayed, achieving the dynamic test to a certain image defect.