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The topology of the distributed cognitive radio network is volatile as influenced by the behavior of primary users, and this condition leads to the large communication overhead and low utilization of spectrum resources. A combination weighted clustering algorithm is proposed in the study to reduce the communication overhead of the distributed cognitive network and maintain the stability of the network structure. First, a clustering algorithm considering the available channel, geographic location, and experienced data (used for collecting the behavior of secondary users (SUs) in the network and the evaluation on it) of SUs is put forward through analyzing the characteristics of the idle channels in cognitive network. Three factors, namely, average channel capacity, stability, and channel quality, are converted into quantifiable values. The cluster head is determined on the basis of the three factors. Then, the cluster members and gateway nodes are determined using the weighting formula and the location information of the cluster head. Results show that the proposed clustering algorithm can generate 15% more clusters than other algorithms and reduce 40% of network communication overhead when the transmission distance between cognitive users and the channel number change. Thus, the stability of the cluster structure is maintained and the communication overhead is decreased. This study provides references for the construction of the stable distributed cognitive network.

X-ray flaw detection is widely used in non-destructive area. The intuitive defect information can be obtained through the X-ray film, which is usually digitized into high greyscale image by a 12-bit or 16-bit, called super 8-bit, industrial scanner. When an ordinary 8bit monitor displays a super 8-bit greyscale image, it appears loss of detail information, blurring of the image appears and other problems. Therefore, in this paper, a pseudocolour enhancement algorithm for displaying high-bit RAW images on low-bit monitor was proposed according to the chromatographic mapping relationship based on the visual characteristics of human eye. First, a high grey-scale pseudo-colour enhancement algorithm, called HOTM-HGL, based on hot metal coding was proposed based on the standard film, whose enhancement effect is better than current mainstream algorithms. Second, aiming at the non-standard film, a new stretching function called RAW-Optical-Stretching was reconstructed to improve HOTM-HGL algorithm, called HOTM-HGLS algorithm, whose display effect on ordinary monitors was improved in further. Finally, HOTM-HGLS algorithm was applied in the detection of X-ray film defect, which was convenient for the capture of defect information in the weld. Compared with the existing algorithms, various indicators have been greatly improved, enriching the amount of information and strengthening the image recognition effects.