blue stretch. TDA9171 Datasheet
YUV picture improvement
processor based on histogram
modification and blue stretch
Supersedes data of 1995 Aug 01
File under Integrated Circuits, IC02
1996 Jun 17
YUV picture improvement processor based
on histogram modiﬁcation and blue stretch
• Picture content dependent non-linear Y and U,V
processing by luminance histogram analysis
• TV standard independent
• Incredible blue stretch
• Optional YC-processing.
The TDA9171 is a transparent analog video processor
with YUV input and output interfaces.
The luminance transfer is controlled in a non-linear way by
the distribution, in 5 discrete histogram sections, of the
luminance values measured in a picture. As a result, the
contrast ratio of the most important parts of the scene will
So as to maintain a proper colour reproduction the
saturation of the −U and −V colour difference signals are
also controlled as a function of the actual non-linearity in
the luminance channel.
Optionally, the YUV blue stretch circuitry can be activated
which offsets colours near white towards blue.
The supply voltage is 8 V.
The device is contained in a 20 lead dual in-line package.
QUICK REFERENCE DATA
plastic dual in-line package; 20 leads; (300 mil); no heat spreader
1996 Jun 17