Operation 19
RM/TM-1405GE Series
3.2.7
Color Interpolation
The Bayer pattern color filter array (CFA) consists of R, G, and B primary colors. Each pixel
represents one of three colors. In order to display or print color images, the signal has to be
converted to RGB output, which has three independent channels (outputs) and sync signals.
Color interpolation software or firmware performs the color preprocessing by
filling the missing color pixels with neighboring pixels. It then separates the
stream of data, (8-bit or 10-bit) into 3 (RGB) data (8-bit x 3) and adds the color
matrix to adjust and balance each of the R, G, and B channels (white balance or
color balance).
The image quality depends on the camera’s own pixel data (including pixel data
independency from neighboring pixels, noise and color filter), and interpolation
of the software algorithm such as 3 x 3 interpolation, 2 x 2 interpolation, color
matrix, white balance capability, etc.
All AccuPiXEL color cameras are carefully designed for maximum color performance. JAI strongly
suggests that you use digital output for the best performance.
Some software is used on board (FPGA or DSP) to perform the interpolation. Other software simply
uses the host computer’s memory and CPU. The processing speed may vary depending on the
architecture and speed of the computer.
3.3
Electronic Shutter
The TM-1405GE has a substrate drain-type shutter mechanism which provides a superb picture at
various speeds without smearing. A built-in flexible shutter speed control selects the electronic
shutter rate from 1/30 to 1/21,000.
With VINIT high (CC1), the CCD keeps discharging. With an active low pulse to VINIT, the camera
resets and purges the charge momentarily. Then it starts integrating for the period of shutter control
set by either an external pulse width or internal shutter control. Progressive scanning permits a full
1040 lines of vertical resolution, as compared to a conventional CCD camera which captures only half
the vertical lines per shutter.
3.4
External Sync
The TM-1405GE accepts an external synchronization of standard HD and VD on CC3 and CC4 of the
Gigabit Ethernet connector for general locking to an external source. The tolerance is ±2% horizontal
frequency.
3.5
Asynchronous Reset
The TM-1405GE camera includes the following modes to control the asynchronous reset and shutter
speed:
•
Async No Shutter (recommended for strobe applications)
•
Async Programmable shutter
•
External VINIT with Pulse Width (No-Delay Shutter)
3.5.1
Async No Shutter
Async No Shutter allows for standard strobe and back-to-back strobing applications (strobing both
before the transfer gate and right after).
