[LineZone] - flip in/out line crossing directions

[harshaneo17]

Description

Between supervision-0.17.0 and supervision-0.18.0, releases in/out of the direction of the crossing were accidentally changed. Given that LineZone is one of the oldest features we have we do not want to make life difficult for users and want to restore the previous behavior. The change made in this PR, most likely in this line, is responsible for the change in behavior.

supervision/supervision/detection/line_counter.py

Line 140 in 0ccb0b8

self.vector.cross_product(point=anchor) > 0 for anchor in box_anchors

Minimal Reproducible Example

You can easily confirm the crossing direction change between supervision-0.17.0 and supervision-0.18.0 releases using this notebook. Here are example results.

supervision-0.17.0

vehicle-counting-result-with-counter-0.17.0.mp4

supervision-0.18.0

vehicle-counting-result-with-counter-0.18.0.mp4

Additional

• Note: Please share a Google Colab with minimal code to test the new feature. We know it's additional work, but it will speed up the review process. The reviewer must test each change. Setting up a local environment to do this is time-consuming. Please ensure that Google Colab can be accessed without any issues (make it public). Thank you! 🙏🏻

[SkalskiP]

Hi @harshaneo17 👋🏻 Thanks for your interest in supervision. I just confirmed. You are right. Let me update the task title and description.

[Kadermiyanyedi]

Hi, I am interesting with this task. Can you assign me

[onuralpszr]

@Kadermiyanyedi you already have experience with linezones it should be easy for you handle it, good luck 👍 😉

[SkalskiP]

Good luck, @Kadermiyanyedi 🤞🏻 Most likely, you need to change > into <. But that's just my guess.

[Kadermiyanyedi]

Good luck, @Kadermiyanyedi 🤞🏻 Most likely, you need to change > into <. But that's just my guess.

Yes, you are right :) I changed the ">" character and opened PR :) Thank you very much for your guidance and detailed job description.