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PX4 / PX4-Flow

Firmware for PX4FLOW board
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Binning #116

Open galdalali opened 5 years ago

galdalali commented 5 years ago

Can someone explain the idea behind the binning operation?

Thanks, Gal.

const float focal_length_px = ((global_data.param[PARAM_FOCAL_LENGTH_MM])
            / (4.0f * 6.0f) * 1000.0f); //original focal lenght: 12mm pixelsize: 6um, binning 4 enabled
mike239x commented 4 years ago

The camera (MT9V034) has standard output of 752x480, but we use 4x4 binning, so the images have size of 188x120. So a single pixel on the resulting image has size of 24μm instead of original 6μm.

timarnold commented 4 years ago

In the paper describing the PX4 (Honegger, "An Open Source and Open Hardware Enabled Embedded Metric ..."), it says "When pixel binning is enabled...", implying binding is a configurable parameter. Based on the code repository, it looks like this is fixed at binning 4. Which is correct? Thanks!

tpetri commented 4 years ago

The paper references the Aptina MT9V034 sensor at that point in the text, the context being: Natively the sensor allows 60Hz at 752Hx480V, but if you activate binning [on the sensor] it can go upto 250Hz at 188Hx120V. So yes, it is a configurable parameter of the hardware sensor itself and this configuration is done in the code, it is set to 4. Implying from the paper that it is a user configurable setting over the params interface goes a bit far, if you hoped for that ;)

timarnold commented 4 years ago

Thanks! This is very helpful. I appreciate it.