
Figure 38.12
Compression
ratio control in JPEG
is
effected by altering the
quantizer matrix: The larger
the entries in the quantizer
matrix, the higher the
compression ratio. The
higher the compression ratio,
the higher the reconstruc-
tion error. At some point,
compression artifacts will
become visible.
J PEG performance is loosely characterized by the error
between the original image data and the reconstructed
data. Metric such as mean-squared error (MSE) are used
to objectify this measure; however, MSE (and other
engineering and mathematical measures) don't neces-
sarily correlate well with subjective performance. ...