Sigma LBA-708 사용자 설명서
When Frame Summing is enabled, the display will update with the summed results only after all
frames have been received. Any calculations will similarly be performed only after all frames have been
received.
Notice: When Frame Summing is enabled and you click on Stop!, the LBA will immediately abort the collection of
frames for summing and will display the last completed set of summed data. Any frames that were in the process of
being summed are discarded, thus when you again click Start! a totally new summing process begins.
frames for summing and will display the last completed set of summed data. Any frames that were in the process of
being summed are discarded, thus when you again click Start! a totally new summing process begins.
6.26 Gamma Correction
If your camera has a gamma value less than or greater than 1, the LBA can be set to correct for your
cameras non-linear response. Enter the gamma of the camera in the Gamma edit control in the
cameras non-linear response. Enter the gamma of the camera in the Gamma edit control in the
Camera.. dialog box. Each pixel of each new frame of data will be automatically corrected as defined
in the equation shown below. If you enter a value of 1, gamma correction is disabled.
P
P
Z
z
g
×
=
/
1
Where:
z
=
Gamma corrected pixel intensity
Z
=
Uncorrected pixel intensity value
g
=
Gamma
P =
255/1023/4095/16383/32767
Notice: Be sure of your Gamma correction value. If necessary, run a response curve on your camera. Standard
published gamma values are usually averages for particular tube types and may not always be adequate for
obtaining the desired accuracy. Also, be wary of gamma values less than 1 published for CCD cameras. These
values are usually approximations obtained by using two-piece linear fits to an exponential gamma curve.
Whenever possible use CCD cameras which are settable to a gamma of 1.
published gamma values are usually averages for particular tube types and may not always be adequate for
obtaining the desired accuracy. Also, be wary of gamma values less than 1 published for CCD cameras. These
values are usually approximations obtained by using two-piece linear fits to an exponential gamma curve.
Whenever possible use CCD cameras which are settable to a gamma of 1.
Operator’s Manual
LBA-PC
Doc. No. 10654-001, Rev 4.10
145