Added homography mappings to heatmap annotator

[tobieabel]

Description

Please include a summary of the change and which issue is fixed or implemented. Please also include relevant motivation and context (e.g. links, docs, tickets etc.).

List any dependencies that are required for this change.

Hi - first time contributor (to any open source project) and a self taught amateur when it comes to coding so be kind! Avid user of supervision and Roboflow tools so hopefully this is useful.
Added some cv2 code for creating a homography mapping and then applying it to the heatmap annotator. Motivation for this is that many clients I work with want to see the heatmap annotations on an overlay of a floorplan rather than from the point of view of the camera. This is a standard 'footfall' use case when tracking people in retail or warehouse environments.

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

How has this change been tested, please provide a testcase or example of how you tested the change?

Sorry, didn't really understand how I am meany to provide a test case, in your documentation it simply says 'we use pytest'. I have tested this in my own streamlit app which I use with clients and have a simple unit test I use which I am happy to submit if told how, but I don't think it would work with your setup.

YOUR_ANSWER

Any specific deployment considerations

For example, documentation changes, usability, usage/costs, secrets, etc.
None that I know of

Docs

• Docs updated? What were the changes:
  Added to the doc strings for the heatmap annnotator in a way that made sense to me but may be to wordy for you guys based on your other examples

[CLAassistant]

All committers have signed the CLA.

[onuralpszr]

@tobieabel could you please create google collab for us to see it looks as well ? visual result would be great

[tobieabel]

Hi @onuralpszr I'll give it a go, not used colab much before and not sure how to use the video and images I've created mappings for within the colab environment, they're currently on my hard-drive. I'll let you know if its successful