The information contained in this document is not subject to Export Control Regulation in Canada.
50
Features and Configuration Options
Calibir GXM640 IR Camera User's Manual
Contrast Enhancement
The native output of the Calibir GXM640 sensor is 16-bits. The contrast enhancement
mechanism is implemented when the pixel output is 8-bits. Contrast enhancement maps
the 16-bit image to 8-bits to output high quality, well-contrasted images, regardless of
the temperature differences found in the scene.
Note: For GigE Vision digital output, the camera output pixel format can be set to
either 16 or 8-bits (monochrome or YUYV). 16-bit output is FPN corrected, but
does not use any contrast enhancement features.
Contrast Mode
The Contrast Mode (contrastMode feature) determines how the contrast is performed. 3
contrast modes are available:
For all contrast modes, values that fall outside the mapped range are rendered as 0 or
255.
Values mapped to 255
Values mapped to 0
16-bit Histogram
0
255
0
65535
Range of pixels
to map to 8-bits
Figure 15: Contrast Enhancement Mapping 16-Bit to 8-bit
Adaptive modes analyze the 16-bit image to determine the average pixel value and then
use this value to determine the DN values to map to 8-bits. Recommended contrast
values for most applications is between 100 and 150. When contrast is set to the
maximum value (255), the image is nearly binarized (pixels above the average value in
the 16-bit image set to 255 and those below the average value set to 0).