Updated lite/examples/object_detection/raspberry_pi/utils.py and changed requirements.txt

[abhaymathur21]

I tried running the object detection example provided in the examples library of tensorflow lite but it gave me an error (Error 1) that I could not solve no matter what and I found out that the tflite-support 0.4.4 version was deprecated and did not work on raspberry pi 4 b so I downgraded it to 0.4.0

Error 1 (from above paragraph):

But when i did that it still gave me an error (Error 2) so i traced the error back all the way to the utils.py file in the same folder and figured out what the problem was in the code.

Error 2 (from paragraph above):

Problem was as follows:

Incorrect variable names were used in the utils.py file in lite/examples/object_detection/raspberry_pi
I changed line 48 from "category = detection.categories[0]" to "category = detection.classes[0]"
and line 49 from "category_name = category.category_name" to "category_name = category.class_name"

After making these changes the code worked perfectly on my raspberry pi 4 b

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