In JPEG, each nonzero AC coefficient is described by a composite 8-bit value I='nnnnssss', where 'nnnn' codes the runlength and 'ssss' codes the category. Every DCT coefficient has a category $k$, where values are in the range $\left[2^{k-1}, 2^{k}-1\right]$ or $\left[-2^{k}+1,-2^{k-1}\right]$, with $1 \leq k \leq 10$ for the baseline system. For category $k$, it is necessary to send $k$ bits to specify the sign and the magnitude of the actual DCT coefficient itself.
The 4 bits 'nnnn' give the position of the current coefficient relative to the previous nonzero coefficient, i.e., the runlength of zero coefficients from the previous nonzero coefficient. The runlengths specified by 'nnnn' may range from 0 to 15 , and a separate symbol, $I=' 11110000$ ' $=240$ represents a runlength of 16 zero coefficients. If the runlength $16$ zero coefficients, it is coded by using multiple symbols. A special symbol, $\mathrm{I}=0$, is used to code the end of block (EOB), signaling all remaining coefficients in the block are zero.
The composite symbols for each block are then Huffman coded, followed by additional bits for the sign and magnitude of the actual DCT coefficient itself.
Question: How many elements are there in the total symbol set for Huffman coding, encompassing categories, runlengths, and additional symbols? (we're not concerned with the sign and magnitude bits, here.)

Question

In JPEG, each nonzero AC coefficient is described by a composite 8-bit value I='nnnnssss', where 'nnnn' codes the runlength and 'ssss' codes the category. Every DCT coefficient has a category $k$, where values are in the range $\left[2^{k-1}, 2^{k}-1\right]$ or $\left[-2^{k}+1,-2^{k-1}\right]$, with $1 \leq k \leq 10$ for the baseline system. For category $k$, it is necessary to send $k$ bits to specify the sign and the magnitude of the actual DCT coefficient itself.
The 4 bits 'nnnn' give the position of the current coefficient relative to the previous nonzero coefficient, i.e., the runlength of zero coefficients from the previous nonzero coefficient. The runlengths specified by 'nnnn' may range from 0 to 15 , and a separate symbol, $I=' 11110000$ ' $=240$ represents a runlength of 16 zero coefficients. If the runlength $>16$ zero coefficients, it is coded by using multiple symbols. A special symbol, $\mathrm{I}=0$, is used to code the end of block (EOB), signaling all remaining coefficients in the block are zero.
The composite symbols for each block are then Huffman coded, followed by additional bits for the sign and magnitude of the actual DCT coefficient itself.
Question: How many elements are there in the total symbol set for Huffman coding, encompassing categories, runlengths, and additional symbols? (we're not concerned with the sign and magnitude bits, here.)

Quizplus · Accepted Answer

The Answer of In JPEG, each nonzero AC coefficient is described by a composite 8-bit value I='nnnnssss', where 'nnnn' codes the runlength and 'ssss' codes the category. Every DCT coefficient has a category $k$, where values are in the range $\left[2^{k-1}, 2^{k}-1\right]$ or $\left[-2^{k}+1,-2^{k-1}\right]$, with $1 \leq k \leq 10$ for the baseline system. For category $k$, it is necessary to send $k$ bits to specify the sign and the magnitude of the actual DCT coefficient itself.
The 4 bits 'nnnn' give the position of the current coefficient relative to the previous nonzero coefficient, i.e., the runlength of zero coefficients from the previous nonzero coefficient. The runlengths specified by 'nnnn' may range from 0 to 15 , and a separate symbol, $I=' 11110000$ ' $=240$ represents a runlength of 16 zero coefficients. If the runlength $>16$ zero coefficients, it is coded by using multiple symbols. A special symbol, $\mathrm{I}=0$, is used to code the end of block (EOB), signaling all remaining coefficients in the block are zero.
The composite symbols for each block are then Huffman coded, followed by additional bits for the sign and magnitude of the actual DCT coefficient itself.
Question: How many elements are there in the total symbol set for Huffman coding, encompassing categories, runlengths, and additional symbols? (we're not concerned with the sign and magnitude bits, here.)

In JPEG, Each Nonzero AC Coefficient Is Described by a Composite