Infer wrong values of bounding box on NPU

[MiloJan]

Hello NXP,

Our program can use the NPU to achieve acceleration using the tflite VX delegate, but can't obtaine the same result as the CPU.

The label value can be obtained correctly, but the value of the bounding box is always 0.

Our environment:

Board: i.MX 8M Plus EVK

System: kirkstone-5.15.71-2.2.0

Tflite Mode: Yolov v7.0

Is there something we didn't notice?

[MiloJan]

Hello @Dhruvit ,

How is it. Could you reproduce that?

[Dhruvit · Accepted solution]

Hi @MiloJan,

I hope you are doing well.

Please find a response from the engineering team below.

One can use the attached patch to fix the issue on the 5.15.71_2.2.0. Use the Yocto SDK to build the libvx_delegate.so.

The steps are as below:

1. Setup the Yocto SDK 5.15.72.(Refer to the i.MX Yocto Project User's Guide)

2. bitbake the vx_delegate, and use the patch by the command

bitbake tensorflow-lite-vx-delegate

cd imx-yocto-bsp/8mp_5.15.72_2.2.0/build-xwayland/tmp/work/armv8a-poky-linux/tensorflow-lite-vx-delegate/2.9.1-r0/git

git apply diff.patch

bitbake -c compile -f tensorflow-lite-vx-delegate

bitbake -c build -f tensorflow-lite-vx-delegate

the libvx_delegate.so will be generated in ../image/usr/lib/

3.copy the libvx_delegate to the broad path /usr/lib/

Thanks & Regards,
Dhruvit Vasavada

[MiloJan]

Hello @Dhruvit,

This works for us. Thanks.

[Dhruvit]

Hi @MiloJan,

I hope you are doing well.

I have reproduced it and I think the root cause is the vxdelegate driver update.

I am checking the two branch differences and the commit log.

I will update here ASAP.

Thanks & Regards,
Dhruvit Vasavada

[Dhruvit]

Hi @MiloJan,

I hope you are doing well.

I am trying to reproduce this issue on my end.

I will get back to you once done.

Thanks & Regards,
Dhruvit Vasavada