Digital output cameras enhance image processing applications

Video cameras designed for CCTV applications usually provide an analog composite video output signal. In most digital image processing applications, the analog video output from the camera is converted into a digital format by an analog-to-digital conversion process. In a conventional CCD based camera, the CCD image sensor generates a sampled analog signal which is processed to create a composite analog video output. At the input of an image processing system, the composite analog video from the camera is digitized before any image processing is performed. If the digitization is performed on the sampled analog output of the CCD, within the camera, then the two-step data conversion process is replaced by a single-step process. In addition, the one-to-one correlation between charge sites on the CCD imager and the pixels in frame memory of the image processor leads to greater precision during image processing. This has led to the development of the Cohu 4110 series of cameras incorporating an eight-bit digital video output. This paper deals with the benefits of using a digital output camera as well as some of the possible applications