Color oCAM latency

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Color oCAM latency

Unread postby prensing » Tue Mar 27, 2018 1:31 am

Has anyone measure the latency (lag) of the color oCAM (oCam-1CGN-U)? That is, I would like to know the end-to-end lag of the camera, how many milliseconds between when something happens and it is displayed on the screen.

Thanks.
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Re: Color oCAM latency

Unread postby prensing » Mon Jun 11, 2018 12:49 am

Still hoping some has some info on this.
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Re: Color oCAM latency

Unread postby WITHROBOT » Thu Jun 14, 2018 8:16 pm

I hope the following gives you some help to understand the operation of the oCam cameras.

The image captured by the image sensor is sent to the host system frame-by-frame. Therefore, from the occurrence of an event to the transmission of the image data, there can be a maximum of one frame time delay, where the frame time depends on the FPS you chose.

The image data received by a host system goes into a FIFO image buffers.
More specifically,
- The image data received by a host receiver fills the last empty buffer. If there is no empty buffer, the image data sent by the camera is simply discarded.
- An application program reads the image frame data which was stored first into the buffers.

Let's say there are N buffers in your host system, your application reads the image at T1 period and the image from the camera is written into the buffer at T2 period.

If T1 is smaller than T2, your application can read the image data as soon as it is available on the buffer.

If T1 is larger than T2, there exists some latency on the buffer.
As an example, let's suppose N = 4, T1 = 1 sec, T2 = 0.1 sec.
- At time 0, your application reads the image frame data from the first buffer and the host receiver fills it at time 0 + DELTA_t, where DELTA_t < 0.1 sec.
- At 1 sec, your application reads the image frame data from the second buffer.
- At 2 sec, your application reads the image frame data from the third buffer.
- At 3 sec, your application reads the image frame data from the fourth buffer.
- At 4 sec, your application reads from the first buffer the image frame data which was written at time 0 + DELTA_t. Therefore, you see about 4 seconds latency here.

Of course, there is little additional delay from reading the image frame data to displaying on the screen.
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