8.Features
© China Daheng Group, Inc. Beijing Image Vision Technology Branch 81
If you want to replace all pixel values, it is recommended to use the
LUTValueAll
function. See the
LutValueAll
sample code in the Development User Manual for details.
8.4.5. Defect Pixel Correction
Due to the technical defects of the image sensor, the camera has defect pixels. Some of these defect
pixels are fixed at the same gray value and do not change with the scene, which are called dead pixels. In
acquired images, some pixels may appear significantly brighter or darker than the rest, even if uniform
light is used, resulting in a significant difference between the gray value and the surrounding pixels, which
is called dark pixels or bright pixels.
The defect pixel correction feature minimizes the influence of these sensitivity differences. The camera
identifies pixels that have a significantly higher or lower intensity value than their neighboring pixels
("outlier pixels") and adjusts their intensity value.
The defect pixels affect the visual experience and further image processing. The MARS series cameras
have very few defect pixels. The default switch status is off. If the gain is too large or a higher quality image
is required, the defect pixels correction can be set to on.
8.5. Image Transmission
8.5.1. Calculate Frame Rate
1) Frame Period
You can calculate the frame period of the MARS-U3 series camera by the following formula:
𝑇
𝑓
= 𝑀𝐴𝑋(
𝑊𝑖𝑑𝑡ℎ ∗ 𝐻𝑒𝑖𝑔ℎ𝑡 ∗ 𝑃𝑖𝑥𝑒𝑙𝑆𝑖𝑧𝑒 ∗ 10
6
𝐵𝑎𝑛𝑑𝑊𝑖𝑑𝑡ℎ
𝑈𝑆𝐵
,
𝑊𝑖𝑑𝑡ℎ ∗ 𝐻𝑒𝑖𝑔ℎ𝑡 ∗ 𝑃𝑖𝑥𝑒𝑙𝑆𝑖𝑧𝑒 ∗ 10
6
𝐷𝑒𝑣𝑖𝑐𝑒𝐿𝑖𝑛𝑘𝑇ℎ𝑟𝑜𝑢𝑔ℎ𝑝𝑢𝑡𝐿𝑖𝑚𝑖𝑡
, 𝑇
𝑎𝑐𝑞
, 𝑇
𝑒𝑥𝑝
)
Among them:
𝑇
𝑓
: The camera's frame period, unit:
μ
s.
Width
: The current image width.
Height
: The current image height.
PixelSize
: The size of the pixel, in 8bit mode, the value is 1, and in 10bit/12bit mode, the value is 2.
BandWidth
USB
: The bandwidth of the USB interface, unit: Bps, for details please see
DeviceLinkThroughputLimit
: The limit of the device link throughput bandwidth, unit: Bps, for details please
T
acq
: The acquisition time of the camera, unit:
μ
s, for details please see
T
exp
: T
he exposure time of the camera, unit: μs
.
