User manual

Small Vision System User Manual 49
and manual gain. The shift from auto to manual is controlled by the value set on gain or
exposure.
Similarly, some color cameras can automatically balance the image colors (autowhite),
and some cameras allow manual setting of color balance (manualwhite). Values of 1
indicate the capability is available on the cameras.
int color
If set to 1, then color information is returned by calls to svsVideoGetImage, if the stereo
head supports it.
If set to 0, then no color information is returned.
int gain
int exposure
If either gain or exposure is set to –1, then auto gain is used. If auto gain is not available,
then setting either to –1 will cause an error in svsVideoCheckParameters or
svsVideoSetDigParams.
For manual control, exposure and gain are set on a scale of 0 to 100. For best image quality,
it is preferable to set the exposure high and the gain low.
int contrast
int brightness
For cameras with auto gain, the auto gain performance can be tuned using these two
parameters. They range from 0 to 100, with nominal values of 50. Higher contrast
values increase the contrast of the auto gain facility, while lower numbers decrease it.
Similarly, the brightness value will cause the auto gain to settle on a brighter or darker
image.
These parameters only have effect if the camera supports auto gain, and the gain or
exposure parameter is set to –1, indicating auto gain mode is in effect.
int red
int blue
These parameters are used to set the color balance of the cameras in manual white balance
mode. They range from –40 to 40. Negative values lower the amount of the corresponding
color in an image.
5.2.7 Checking Image Parameters
Before starting a continuous video stream, the SVS system requires that the image parameters be
consistent. In general, this means that the image size, decimation/binning, subwindowing, and vergence
are consistent and implemented by the stereo head. The function svsVideoCheckParameters looks
at an svsSP structure, and returns an error code if the parameters are not consistent. It is recommended
that svsVideoCheckParameters be called before each call to svsVideoStartContinuous.
int svsVideoCheckParameters(svsSP *sp)
Returns an error code if the parameter structure sp is not consistent or implementable;
otherwise returns 0.
Error codes (defined in svs.h):
VIDEO_ERROR_DEC_MODE Decimation mode is not available
VIDEO_ERROR_BIN_MODE Binning mode is not available
VIDEO_ERROR_FRAME_SIZE Frame width or height is not consistent
VIDEO_ERROR_SUBWINDOW Subwindow size is not consistent