4 Functionality
Simultaneous readout mode (exposure time < readout time)
The frame rate is given by the
readout time. Frames per second equal to the inverse of the readout time.
Simultaneous readout mode (exposure time > readout time)
The frame rate is given by the
exposure time. Frames per second equal to the inverse of the exposure time.
The simultaneous readout mode allows higher frame rates. However, if the exposure time
greatly exceeds the readout time, then the effect on the frame rate is neglectable.
In simultaneous readout mode image output faces minor limitations. The overall
linear sensor reponse is partially restricted in the lower grey scale region.
When changing readout mode from sequential to simultaneous readout mode
or vice versa, new settings of the BlackLevelOffset and of the image correction
are required.
Sequential readout
By default the camera continuously delivers images as fast as possible ("Free-running mode")
in the sequential readout mode. Exposure time of the next image can only start if the readout
time of the current image is finished.
e x p o s u r e
r e a d o u t
e x p o s u r e
r e a d o u t
Figure 4.2: Timing in free-running sequential readout mode
When the acquisition of an image needs to be synchronised to an external event, an external
trigger can be used (refer to Section 4.4). In this mode, the camera is idle until it gets a signal
to capture an image.
e x p o s u r e
r e a d o u t
i d l e
e x p o s u r e
e x t e r n a l t r i g g e r
Figure 4.3: Timing in triggered sequential readout mode
Simultaneous readout (interleave exposure)
To achieve highest possible frame rates, the camera must be set to "Free-running mode" with
simultaneous readout. The camera continuously delivers images as fast as possible. Exposure
time of the next image can start during the readout time of the current image.
e x p o s u r e n
i d l e
i d l e
r e a d o u t n
e x p o s u r e n + 1
r e a d o u t n + 1
f r a m e t i m e
r e a d o u t n - 1
Figure 4.4: Timing in free-running simultaneous readout mode (readout time> exposure time)
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Summary of Contents for SM2-D1312-TI6455
Page 1: ...User Manual SM2 D1312 TI6455 VisionCam PS CMOS DSP Camera MAN060 05 2013 V1 0...
Page 2: ......
Page 4: ...2...
Page 8: ...CONTENTS 6...
Page 48: ...4 Functionality Figure 4 28 Example of decimation 2 on image of injection needle 46...
Page 80: ...4 Functionality 78...
Page 110: ...6 Framework Functionalities 108...
Page 116: ...8 Warranty 114...
Page 118: ...9 References 116...
Page 122: ...A Pinouts 120...
Page 123: ...B Revision History Rev 1 0 May 2013 First version 121...
