8.Features
© China Daheng Group, Inc. Beijing Image Vision Technology Branch 90
Figure 8-54 Before sharpness adjustment
Figure 8-55 After sharpness adjustment
Sharpness adjustment
Adjust the sharpness value to adjust the camera's sharpness to the image. The adjustment range is 0-3.0.
The larger the value, the higher the sharpness.
8.4.4. Lookup Table
When the analog signal that is read out by the sensor has been converted via ADC, generally, the raw
data bit depth is larger than 8 bits, there are 12 bits, 10 bits, etc. The feature of lookup table is to replace
some pixel values in the 8 bits, 10 bits, and 12 bits images by values defined by the user.
The lookup table can be a linear lookup table or a non-linear lookup table, created entirely by the user.
You can also use the
LutValueAll
function to create an entire lookup table.
1) How it works
a) LUT is short for "lookup table", which is basically an indexed list of numbers.
b) In the lookup table you can define replacement values for individual pixel values. For example, you
can replace a gray value of 0 (= minimum gray value) by a gray value of 1023 (= maximum gray value
for 10-bit pixel formats). This changes all completely black pixels in your images to completely white
pixels.
c) Setting a user-defined LUT can optimize the luminance of images. By defining the replacement values
in advance and storing them in the camera to avoid time-consuming calculations. The camera itself
has a factory default lookup table, and the default lookup tables for MARS-880-13GM-P, MARS-880-
13GM-P ETR, MARS-1230-9GM-P, MARS-2621-4GM-P ETR, MARS-2621-4GM-P NIR ETR, MARS-
2622-4GM-P ETR, MARS-2622-4GM-P NIR ETR, MARS-3140-3GM-P and MARS-3140-3GC-P
cameras do not affect image luminance.
2) Creating the user-defined LUT
MARS-3140-3GM/C-P supports creating the user-defined lookup tables. To create a lookup table, you
need to determine the range of
LUTIndex
and
LUTValue
parameters by the maximum pixel format
supported by the currently used camera.
