Acquisition and Digital Images Processing, Comparative Analysis of FPGA, DSP, PC for the Subtraction and Thresholding.

Given the need to reduce the time involved in image processing, we found that is necessary to use new methods to improve the time response. In our application of real time tracking of different species in the study of marine animal conduct, a reduction in the image processing time provides us with more information that allows us to better predict the animal’s escape trajectory from a predator. Nowadays, photographic cameras can deliver photographs in various formats, hence the need to provide them with pre-processing in order to deliver the required format. Although Photographic cameras are available that can deliver photos without pre-processing, the format provided is the Bayer format. A characteristic of this format is that we obtain the images almost directly from the CCD sensors and from the analogical to digital converter with no pre-processing. The only requirement is a deserialization step and registers in parallel whose role is to place the Bayer format image in a memory for the investigation (Lujan et al., 2007). In the initial method in our project, the camera is connected to a Frame Grabber which retrieves the image, converts it to RGB, changing it to a scale of greys and subsequently carries out the necessary processing, the first being the subtraction of the background from the image of the animals under study, followed by the application of blurring. Subtraction of images is widely used when the aim is to obtain the animal’s trajectory (Gonzales et al., 2002), however, we use it to leave only the animals under study, eliminating everything else. A low pass filter (Gonzales et al., 2002) (blurred) is used which unifies any division in some of the animals caused by the subtraction. Occasionally a shrimp would be divided in two due to the kind of background used, recognizing two shrimps instead of one, this error was resolved by the application of the blurring. The new process would involve recovering the image and then to immediately carry out the image processing of subtraction and blurring, saving time by avoiding the use of a Bayer to RGB encoder and the frame grabber. We included a stage of image recovery by a number of deserielizors and registers in order to deliver the image in Bayer format.