Barcode scanning - limit to 1-2 barcode types?

OpenMV Boards
1

Hi guys,

I’m trying to get the speed of the global shutter camera MT9V034 up to 60 fps - right now I can get 24 fps by setting the framesize to QVGA (320x240px) and windowing to 320x20px. If I go to HQVGA (240x160) it’s still 24fps.

These tests are being done by pointing the camera at my laptop screen displaying some barcodes - the exposure time as reported by sensor.get_exposure_us() is 15ms.

25 fps would be 40ms per frame, so the remaining 25ms must be for scanning the image and sending the barcode by mqtt. So even if we could do 0 exposure time, it should max out at 1/25ms = 40fps.

I timed the message creation and mqtt stuff and it seems to take about 1 ms.

We could get by with scanning just 1-2 types of barcode instead of all 16, but it looks like right now there’s no way to limit the types scanned, just the region of interest -

https://docs.openmv.io/library/omv.image.html#image.image.Image.image.find_barcodes

Is that something we could add to the find_barcodes params?

Thank you!

2

Sorry, zbar scans for all types at the same time.

You can modify the code in here to disable that: https://github.com/openmv/openmv/blob/master/src/omv/imlib/zbar.c

3

Okay thanks, I’ll see what I can do with it…