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Figure 1
Compression scheme. (a) Compression of a single 16-bit 512 × 512-pixel diffraction frame. The pixel values of each data block are stripped of their most significant bits. For a block size of 3 with values 5, 0, 3 shown here, the encoded bits would be: 101 (denoting 5), 000 (denoting 0) and 011 (denoting 3). This block of data can therefore be encoded as three values of 3 bits each. The encoded 101000011 block would be pushed into the `Terse' object. (b) Each compressed data block is described by a variable-sized block descriptor, which is preceded by a single bit. If the bit is set, the block descriptor is identical to the previous one. If the bit is not set, a new block descriptor follows. In this scenario, bits 2 to 4 define how many bits are used per value of the encoded block. If all three subsequent bits are set, the block descriptor is expanded to allow encoding of pixel values that require up to 64 bits. The black square embedded in the image represents a 15 × 15-pixel scale for reference.

ISSN: 2053-2733
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