Detailed description

VL6522

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Typically, the visual effect is at its worst where the distance from the optical centre to the

edge of the image is at its maximum and manifests itself as the familiar ‘darkening of the

image corners’.

4.1.6

Channel offset

The channel offset module is used to add or subtract a programmable offset from each of

the four Bayer color channels of the incoming IDP. These offsets are typically used to

remove a data pedestal or cancel a dark offset introduced at an earlier stage in the pipe.

4.1.7

Channel gain

The channel gain module is used to apply a programmable gain to each of the four Bayer

color channels of input data. These gains are used as controls of Automatic Exposure

Control (AEC) and Automatic White Balance (AWB).

4.1.8

Defect correction

This function runs a defect correction filter over the data in order to remove defects from the

final output. This function has been optimized to attain the minimum level of defects from the

system.

4.1.9

Interpolation (demosaic)

The interpolation module converts Bayer pixel data to RGB and applies an anti-alias filter to

the data.

4.1.10

Color matrix

The color matrix correction transformation is performed on the outputs of the interpolation

module.

4.1.11

Sharpening

The sharpening module’s function is to add a certain amount of peaking components to the

original interpolated RGB. Indeed, the interpolation process involves a certain degree of

low-pass filtering that blurs the original sharpness of the image.

In order to realize 2-dimensional sharpness easily, the sharpening filter is only applied on

the green components (green carries the highest luma component). The output of the filter

is re-injected into the R, G, and B components from the matrix, via a process called coring.

4.1.12

Gamma correction

The gamma correction module applies a non-linear compensation to the IDP RGB data

stream in order to achieve correct reproduction of intensity on the host display.

4.1.13

RGB to YUV 422

Conversion of RGB to YUV 4:2:2. The YUV comprises luminance (Y) and chrominance (U

and V) components.