Abstract: A camera field-of-view is mapped with full depth-of-focus into electronic memory. Data concerning image intensities at selected points in image space are stored, along with data concerning the distances between the camera and these points in image space. Images with any focus and depth-of-focus can be generated by scanning the electronic memory during a reading thereof and convolving the data concerning image intensity with an adjustable-bandwidth low-pass spatial filter. The bandwidth of that filter is adjusted dependent on the data concerning distances between camera and points in image space. This image storage and image retrieval procedure conserves the size of electronic memory required to store and retrieve images with any focus and depth-of-focus.

Abstract: Digital values in a moving window are compared by an operator having nine comparators (18) connected to line buffers (16) for receiving a succession of central pixels together with eight neighborhood pixels. A single bit of program control determines whether the neighborhood pixels are to be compared with the central pixel or a threshold value. The central pixel is always compared with the threshold. The comparator output, plus 2 bits indicating odd-even pixel/line information about the central pixel, addresses a lookup table (20) to provide 14 bits of information, including 2 bits which control a selector (22) to pass either the central pixel value, the other 12 bits of table information, or the bit-wise logic OR of all neighboring pixels.