8. Capturing Images 93
Note
When enabling horizontal binning, ImageStartX and ImageSizeX val-
ues will be halved. Vertical binning mode inuences ImageSizeY and
UnitImageSizeY instead.
Note
For two-lines monochrome sensors only: when acquiring a moving target, en-
abling the LineDelay control (see Section 5.7) together with vertical binning
may be recommended.
8.5 PIXEL FORMAT
The pixel format parameter controls the format used for sending image pixels to the PC. The available
formats depend on the camera model and the selected video mode:
Pixel Format NECTA Color model NECTA Monochrome model Video Mode Bytes per pixel
MONO8 0 1
MONO16 0 / 2 2
YUV422 N.A. 0 / 2 2
RGB24 N.A. 0 / 2 3
RAW8 1 1
RAW16 1 2
Table 8.1: Available pixel formats
When MONO8 is selected, the camera sends the 8 most signicant bits of the image pixel luminance
(Y) to the PC. When MONO16 is selected, the camera sends all 16 bit of the image pixel luminance (Y),
sampled using the resolution selected by the ADC resolution control and aligned to the most signicant
bit; pixel data are little endian ordered.
Color cameras feature also YUV422 and RGB24 formats, providing color images; when one of these
formats is selected, the camera performs an internal processing called demosaicing, which reconstructs
the actual color of each pixel sampled according to the Bayer lter (see Figure 3.1).
The RGB24 format uses 3 byte (24 bit) per pixel; it may therefore represent 16.7 million colors.
When the YUV422 format is selected, after demosaicing the camera re-encodes the internal RGB rep-
resentation: for each pair of pixels, the camera sends 2 byte for luminance (one per pixel) and 2 byte
for chrominance, common to both pixels. It thus implements a simple 3:2 compression, still providing
excellent image quality.
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