pub fn idct_block(quantized: &[i16; 64], qt: &[u16; 64]) -> [f64; 64]Expand description
Dequantize + 8×8 IDCT → 64 spatial-domain pixel values.
Input: quantized DCT coefficients in natural (row-major) order. Output: pixel values (approximately 0–255 after +128 shift).