HD49815 View Datasheet(PDF) - Hitachi -> Renesas Electronics

Part Name

Description

Manufacturer

HD49815

Digital Camera Signal Processor

Hitachi -> Renesas Electronics 

HD49815TF

c. Luminance correction

The ratio of the red and blue levels changes according to the color temperature of the imaged object.

For example, if a red object is imaged at a low color temperature, the luminance level increases and

the object appears to have a lower chrominance. Therefore, the luminance correction circuit

performs luminance-correction processing to implement color depth reproduction.

The luminance-correction circuit is set in State Data SP_A5 [12, 13].

d. Y setup

Since the OB clamp processes the signal, the black level of the 10-bit signal input to the

HD49815TF is fixed to 48/1024. The Y-setup circuit subtracts 48 at the black level. However,

when 48 at the black level differs due to the noise mixed in the analog signal, the Y-setup circuit

subtracts that value.

The Y-setup circuit is set in State Data SP_A5 [6].

e. Gamma correction

The gamma-correction circuit implements the gamma-correction processing for the separated Y

signal. Four kinds of values can be set independently, according to the input-signal level, to acquire

optimal gamma characteristics: the gamma input limit, the gamma knee coefficient, the gamma

coefficient, and the gamma black clipping.

The gamma correction circuit is set in State Data SP_A5 [1 to 4].

f. Highlight enhancer

For input-Y signal levels in excess of 100 IRE, the highlight enhancer implements highlight

enhancer processing.

This circuit is set in State Data SP_A5 [0, 5, and 14].

g. Fade

The fade circuit amplifies the luminance signal by a factor of 0 to 1.

This circuit is set in State Data SP_A5 [9].

4. Zoom, encode block, TG, SSG, and AWB and AE detection blocks

a. Zoom processing

The Y, R-Y, and B-Y signals completed the color-signal processing and the luminance-signal

processing can be electronically zoomed by a factor of 1 to 256.

After clipping CCD signals for V direction, zoom circuit clips these signals for H direction, and

expand these signals for H and V directions.

The zooming times and the read starting position for the V and H directions are set in State Data

TM_A2 [3, 4, 5, 6, 8, and 9] and ZM_A0 to 6.

b. Encode block

This circuit encodes the signals completed the color-signal processing, the luminance-signal

processing, and the zoom processing as the NTSC/PAL TV-monitor method.

A DAC that converts the digital signal to an analog signal is provided. The DAC has two channels:

one for R-Y signals and one for B-Y signals.

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