Apparatus and method for processing an image data stream by comparing first and second checking data streams

A camera controller (1) with an image data stream input (2) and an image data stream output (4), wherein a first image data stream path (3) and a second image data stream path (5) are formed. An image processing unit (6) is arranged in the second image data stream path (5). A switching unit (7) is controlled by a comparison unit (8). The comparison unit (8) compares a first checking data stream (9), which was diverted from an image data stream (1) upstream of the image processing unit (6), and a second checking data stream (10), which was diverted from the image data stream downstream of the image processing unit (6). The image data stream paths are switched via the switching unit (7) if the deviation of the second checking data stream (9) from the first checking data stream (10) exceeds a threshold value.