工业射线底片图像数字化系统的设计

Design of Image Digitization System for Industrial Radiographic Films

工业射线底片由于其黑度大,图像信息量大而使其数字化成为一个难题.采用机器视觉的方法,设计了一套工业射线底片的图像的数字化系统,由光源、成像系统和计算机软硬件系统构成.采用平面亮度强光灯透照底片解决黑度大问题,用亮度无级可调灯解决不同黑度底片的数字化,用暗箱屏蔽环境光以提高图像质量,针对面阵CCD精度的不足,提出用双CCD的方法成像,同时提出了图像拼接的方法并实现拼接.实验结果表明,拍摄的图像质量较好,分辨率达到5.3 lp/mm,不同CCD拍摄的图像可实现无缝拼接.

It is a difficult problem to digitize the image on an industrial radiographic film due to its high blackness and mass image information. A new image digitization system for industrial radiographic films is designed. The system is composed of a light source, an image-forming system,and computer hardware and softwares. A plane intensive light is used to transilluminate a film to resolve the high blackness. A lamp with adjustable brightness is introduced to digitize films with different blackness. A light-tight box is adopted to shield ambient light and improve quality of image. For the low precision of one CCD, two CCDs are used. A splicing method is advanced in order to splice two images together. Experiment results indicate that the image quality is perfect, image resolution ratio is up to 5. 3lp/mm, and two images can be spliced without error.