Space-dependent binary image processing within a 64x64 mixed-mode array processor

This paper describes the binary (B/W) processing capabilities of a 64x64 mixed-mode array processor (MIPA4k). In addition to having space-independent weights (templates), the eight-connected B/W processing core is equipped with the option of space-dependent templates and bias. The template coefficients are 1-bit programmable, whereas the bias is programmable with two bits. The local templates and bias are stored in digital memories within the processing elements. These memories are accessible by the gray-scale processing cores of MIPA4k, making possible the setting of templates and bias based on the processing results of the gray-scale front-end. Alternatively, the coefficient circuits can be configured so that space-dependent weights are used, but, instead of letting the neighbor cells to control the coefficient circuits, the contents of the local memories can be used to control them. Therefore, 9-input threshold logic operations of the contents of local memory can be performed. This is useful in, e.g., identifying local binary patterns (LBP) in parallel. The realization of the B/W processing unit is described and selected measurement results of the 64x64 array are shown.