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This functions parses the huffman table and try to figure out if huffman
optimizations are applied on the image or not. If segmentData has more bytes after
parsing first HT, that means DHT segment has multiple huffman tables.
Structure of DHT (Define Huffman Table) segment.
- HT information (1 byte): (bit 0 = LSB and bit 7 = MSB)
bit 3..0: index of HT (3..0, otherwise error)
bit 4 : type of HT, 0 = DC table, 1 = AC table
bit 7..5: not used, must be 0
- 16 bytes: number of symbols with codes of length 1..16, the sum of these
bytes is the total number of codes, which must be