Merge pull request #24397 from richard28039:add_fcnresnet101_to_dnn_sample

Added PyTorch fcnresnet101 segmentation conversion cases #24397

We write a sample code about transforming Pytorch fcnresnet101 to ONNX running on OpenCV.

The input source image was shooted by ourself.

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [X] I agree to contribute to the project under Apache 2 License.
- [X] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [X] The PR is proposed to the proper branch
- [ ] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake

samples/dnn/models.yml

@@ -178,3 +178,15 @@ fcn8s:
   height: 500
   rgb: false
   sample: "segmentation"
+
+fcnresnet101:
+  load_info:
+    url: "https://github.com/onnx/models/raw/fb8271d5d5d9b90dbb1eb5e8e40f8f580fb248b3/vision/object_detection_segmentation/fcn/model/fcn-resnet101-11.onnx"
+    sha1: "e7e76474bf6b73334ab32c4be1374c9e605f5aed"
+  model: "fcn-resnet101-11.onnx"
+  mean: [103.5, 116.2, 123.6]
+  scale: 0.019
+  width: 500
+  height: 500
+  rgb: false
+  sample: "segmentation"

samples/dnn/segmentation.py

@@ -14,7 +14,7 @@ parser = argparse.ArgumentParser(add_help=False)
 parser.add_argument('--zoo', default=os.path.join(os.path.dirname(os.path.abspath(__file__)), 'models.yml'),
                     help='An optional path to file with preprocessing parameters.')
 parser.add_argument('--input', help='Path to input image or video file. Skip this argument to capture frames from a camera.')
-parser.add_argument('--framework', choices=['caffe', 'tensorflow', 'torch', 'darknet'],
+parser.add_argument('--framework', choices=['caffe', 'tensorflow', 'torch', 'darknet', 'onnx'],
                     help='Optional name of an origin framework of the model. '
                          'Detect it automatically if it does not set.')
 parser.add_argument('--colors', help='Optional path to a text file with colors for an every class. '