JAI RM/TM-1327GE Series, Руководство пользователя

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Operation 15
RM/TM-1327GE Series
3 Operation
3.1 Progressive Scanning
The TM-1327GE uses a state-of-the-art progressive scanning interline transfer CCD which scans all lines
sequentially from top to bottom at one frame rate. Like a non-interlace computer screen, it generates a stable,
crisp image without alternating lines and provides full vertical TV resolution of 1040 lines.
The interline transfer architecture is also important to generate simultaneous shuttering. This is different from
full frame transfer architecture, which requires a mechanical shutter or strobe light in order to freeze the
object motion.
The TM-1327GE outputs the progressive scanned image with an electronic shutter in two different formats.
•
Progressive scanning digital - The CCD signal goes through A/D converters 10-bit in, 10-bit/8-bit out. The
digital output is available using the Gigabit Ethernet connector.
•
Analog output - The analog output is the same as 75 ohms, 714mV format available from BNC and 12-pin
connector. Analog video does not conform to the RS-170 standard and is not RS-170 compatible.
3.1.1 Programmable Scan Area
In User Programmable scan mode, users can specify both the start point of the active scan area and the total
active lines through the serial communication commands. The area selected by users is transferred out line by
line. The rest of the lines are dumped out using the fast dump function of the CCD. The frame rate in this mode
varies according to the selected active area (see Section 3.8).
3.2 Bayer Color Filter (Color Versions)
JAI AccuPiXEL series color cameras are high-resolution, high-speed progressive scan CCD cameras. The interline
transfer, progressive scan CCD permits full vertical and horizontal resolution of images acquired at very high
shutter speeds. The electronic shutter, which has speeds to 1/21,000 sec., can be reset asynchronously by
external pulse control. Uniform square pixels provide superior image definition in any orientation. On-chip
micro lenses mean increased sensitivity.
3.2.1 Color Filter Array
JAI 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.
3.2.2 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.