private void jpeg_idct_1x1(int component_index, short[] coef_block, int output_row, int output_col)
{
/* We hardly need an inverse DCT routine for this: just take the
* average pixel value, which is one-eighth of the DC coefficient.
*/
int[] quantptr = m_dctTables[component_index].int_array;
int dcval = REDUCED_DEQUANTIZE(coef_block[0], quantptr[0]);
dcval = JpegUtils.DESCALE(dcval, 3);
byte[] limit = m_cinfo.m_sample_range_limit;
int limitOffset = m_cinfo.m_sampleRangeLimitOffset - RANGE_SUBSET;
m_componentBuffer[output_row + 0][output_col] = limit[limitOffset + dcval & RANGE_MASK];
}