JAI TMC-4200GE User Manual download pdf (Page 71)

Page 59

TM-4200GE Hardware

Operation

9.2.1 Color Filter Array

JAI Inc. AccuPiXEL cameras use Bayer CFA (color filter array) as their standard primary color filter.

This filter provides the most popular color interpolation supported by numerous software suppliers.

The digital format allows the camera to output accurate pixel data, including the color information.

When the data is stored in the frame buffer of a frame grabber or computer, the color information is

easily manipulated to restore the original color images. Because the color filter array contains only a

single R, G or B color in each pixel, the restored image has to fill in colors in the missing pixel

locations. The software uses neighboring pixel information to “guess” the missing colors to make

smooth, clear images. This is called “color interpolation.” Today’s high-speed computers allow such

color interpolation to be done almost in real time. Because these cameras do not contain internal color-

processing circuitry, they are smaller and less expensive than full-function color cameras.

9.2.2 Bayer Color Filter Array (CFA)

The Bayer CFA is an R, G, B primary color filter array. This is the most widely accepted CFA for the

single-chip CCD progressive scan format. This type of array layout has a specific order for each color’s

pixels. Since the human eye’s resolution and color recognition are highest at green, the CFA contains

two greens per each red and blue.

It is critical for the frame grabber and color interpolation to know where the individual color pixels exist

relative to sync (LDV and FDV) timing.

This requirement makes digital output the preferred choice, because the timing relationships are very

accurate

FIGURE 60. Bayer Color Filter Response.

1 2 ... 66 67 68 69 70 71 72 73 74 75 76 ... 91 92

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JAI TMC-4200GE User Manual Page 71