Clean Objdetect module

[vpisarev]

Describe the feature and motivation

object detection is one of the key computer vision tasks where machine learning was used long before deep learning era. Nowadays, with deep learning, the problem is largely solved, at least for common cases.

But objdetect module in OpenCV still contains 'ancient' algorithms. We need to clean it up in OpenCV 5:

• Move HaarCascadeClassifier to opencv_contrib/xobjdetect.
• Move HOGDescriptor to opencv_contrib/xobjdetect.
• Move all Haar/LBP models (opencv/data/*) to opencv_contrib.
• Move/add Yolo postprocessing functions and DetectionModel from dnn to objdetect.
• Possibly move Macbeth color chart detector from opencv_contrib/mcc to this module.
• Maybe add deep learning-based detectors of basic geometric objects like circles and lines instead of traditional algorithms based on Hough transform (which we suggest to remove from Imgproc).

Additional context

No response

[LaurentBerger]

Finally I like mediapipe classification :

[vpisarev]

@LaurentBerger, looks good, but it's probably too much to have a dedicated OpenCV module for each of those tasks. Various image improvements and stylizations can possibly be put to 'photo' module. Detection-related things can be put to 'objdetect'. Image classification and semantic segmentation now belong to dnn module.

[LaurentBerger]

May be :
DNN (4.0) -> DNNCore (5.0)
Objdetect (4.0) -> DNNModels (5.0) with subfolder as in mediapipe

[vpisarev]

@LaurentBerger, we have a dedicated repository opencv_zoo that plays the role of DNNModels :)

[Dhanwanth1803]

@vpisarev Can I work on this? Because I am not sure if only members are working on this.