Dear Duarte,

this example might be an inspiration

usign the zoom basically skips pixels and lines and takes only the one usefull. Not sure if you mean acquisition from the microcontroller or also on the PC via bluetooth (BT). In that later case, most of the time required by the BT communication.


On 20:59, Duarte Dias wrote:

I am using  the e-puck 1176 (VGA camera 480x640 - rotated camera).

I am capturing some full (480 pixels) horizontal lines (1 to 8 lines) applying the zoom factor of 1, 2, 4 and 8 (on the x component which in this epuck camera is the vertical component).

I assume that if I am capturing 4 horizontal lines with zoom 2 its the same of capturing 8 lines with zoom 1 (and so one). The zoom just does the line averaging within groups of 2 lines.

When I capture the images I am using a timer (TIMER1) to quantify the capture duration.

After my experiments from capturing 1 - 8 lines with zoom 1,2,4,8 I have concluded that the capture time is approximatly constant (between 350 and 450), no matter the number of lines we take and the zoom we do.

I have also witnessed a large Jitter between frame captures (the standard deviation of the frame capture times is arround 150ms!).

I was expecting a rise of time when I extracted more lines and no Jitter should exist. Could someone tell me what I could be the cause of this behaviour (expecially the Jitter behaviour).

Duarte Dias

Dr. Gilles Caprari
GCtronic Sagl, Electronics&  Mechatronics
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