AK8853XQ Datasheet, PDF (34/70 Pages) Asahi Kasei Microsystems – NTSC/PAL/SECAM Digital Video Decoder

[AK8853XQ/ VN]
7.22.2 Brightness adjustment
BR[7:0]-bits: For brightness adjustment; settings in 2’s complement;
default value 0x00 (no adjustment)
Brightness adjustment involves multiplication of the 8Bit data luminance signal, after ITU-R BT.601
conversion, by the gain factor setting in this register, as follows.
YOUT = YIN + BR
YOUT: Brightness obtained by the calculation
YIN: Brightness before the calculation
BR: Brightness gain factor (register setting value)
The gain factor can be set in the range -127 to +127 in steps of 1, by 2’s complement entry. If the
calculated value is outside the specified contrast range, it is clipped to the upper ‘254’ or lower ‘1’ limit.
With a control bit 601LIMIT setting of [1], the output will be in the range 16~235.
7.22.3 Color saturation adjustment
SAT[7:0]-bits: For color saturation adjustment; default value 0x80 (no adjustment)
Saturation adjustment involves multiplication of the color signal by the gain factor setting in this
register. The calculated result is U/V demodulated.
The gain factor can be set in the range 0 to 255/128, in steps of 1/128.
7.22.4 Hue adjustment
HUE[7:0]-bits: For hue adjustment; settings in 2’s complement; default value 0x00 (no adjustment)
The AK8853 can perform hue rotation with a phase rotation range of ±45° in steps of about
0.35°.
7.22.5 Sharpness adjustment
Sharpness adjustment is performed on the luminance signal as shown in the following process diagram.
The filter characteristics and the coring level can be selected by following register. A sharp image can be
obtained by selection of the filter with the appropriate characteristics.
SHARP[1:0]-bits
SHCORE[1:0]-bits
Luminance signal
before processing
Filter
Coring
Luminance signal
after processing
Delay
SHARP[1:0]-bits: Settings for filter characteristics selection
SHARP[1:0]-bits
Filter characteristics
[00]
No filtering
[01]
Min
[10]
Middle
[11]
Max
Notes
Filter disabled
—
—
—
SHCORE[1:0]-bits: Settings for coring level after sharpness filtering
SHCORE[1:0]-bits
Coring level (LSB)
[00]
No coring
[01]
±1
[10]
±2
[11]
±3
Notes
Settings apply only to
filtered signal.
Rev-E-00
34
2008/01