Philips Semiconductors
Digital Signal Processor (DSP) for
cameras
Preliminary specification
SAA8110G
RGB-to-YUV block
After RGB processing, the channels are separated in a
luminance and two colour difference path:
Y = 0.299 R + 0.597 G + 0.114 B, U = 0.49 (B − Y) and
V = 0.88 (R − Y) . It also contains two down-sampling
filters for U and V signals.
Y-processing
The luminance component includes several features:
• Contour correction allowing an increase of the
luminance transitions for a sharper picture
• Black stretch function for contrast enhancement in dark
scenes
• False colour detector used by the UV-processing block
to enable the colour killer
• Filters and noise reduction by coring (only in the high
frequency part of the signal).
handbook, full pagewidth
R
9
Y
(0 to 511)
G
B
CONVERSION
MATRIX
DOWN-
8
SAMPLING
& MUX
UV
(−128 to 127)
MGK155
Fig.5 RGB-to-YUV conversion.
handbook, full pagewidth vertical contour
10
(−512 to 511)
(from RGB-separation)
CONTOUR PROCESSING
AND
FALSE COLOUR DETECTION
false colour
Y
(0, 0.5 to 255.5)
9
BLACK STRETCH
+
NOISE
8
REDUCTION
Y
MGK156
1997 Jun 13
Fig.6 Y processing.
9