A stereoscopic camera arrangement is an element made of two camera units, assembled in a stereoscopic module. Stereoscopy (also referred to as “stereoscopics” or “3D imaging”) is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis. In other words, it is the impression of depth that is perceived when a scene is viewed with both eyes by someone with normal binocular vision which is responsible for creating two slightly different images of the scene in the two eyes due to the eyes ‘/camera’s different locations.
Combining 3D information derived from stereoscopic images, and particularly for video streams, requires search and comparison of a large number of pixels that need to be held for each pair of images, where each image out of such a pair is derived from a different image capturing device.
This problem is further enhanced when depth needs to be determined from images derived from webcams, as in order to obtain the required three-dimensional image, the webcams output images should be rectified. During the rectification process, radial lens distortion and sensor rotation should be compensated based on preliminary sensor calibration results.
A hardware chip that is able to carry out such a rectification process, uses typically large memory buffers in order to correct for the displacement of each pixel received from each sensor. These buffers are typically sufficient for only a limited amount of distortion, and when using wide angle lenses for example, these lenses might introduce a higher degree of distortion than a single buffer of several lines can handle, while such a buffer is typically used to rectify the sensor outputs.
The number of lines to be processed corresponds to the maximal radial distortion and rotation that are supported by the system. For example, at 1920×960 pixels images and maximal distortion of 5% on two sensors, one would require the use of 960*0.05=48 lines of 1920 pixels, at 2 bytes per pixels, which amounts to about 3 Mbit of memory. While if three wide lens sensors are used with a maximum distortion of 20%, the resulting memory required of about 18 Mbit, would simply be prohibitive for carrying out such a process.
Thus, in order to provide an adequate answer to the increasing memory requirements, a new approach is proposed by the present invention, one which overcomes the problems discussed above.