• dongdongdong1
  • Python
  • 15.1MB
  • rar
  • 0
  • 10 积分
  • 0
  • 2020-09-08 19:07
## part 1. Introduction Implementation of YOLO v3 object detector in Tensorflow (TF-Slim). This repository is inspired by [Paweł Kapica]( The full details are in [this paper]( In this project we cover several segments as follows:<br> - [x] [YOLO v3 architecture]( - [x] Weights converter (util for exporting loaded COCO weights as TF checkpoint) - [x] Basic working demo - [x] Non max suppression on the both `GPU` and `CPU` is supported - [x] Training pipeline - [x] Compute COCO mAP YOLO paper is quick hard to understand, along side that paper. This repo enables you to have a quick understanding of YOLO Algorithmn. ## part 2. Quick start 1. Clone this file ```bashrc $ git clone ``` 2. You are supposed to install some dependencies before getting out hands with these codes. ```bashrc $ cd tensorflow-yolov3 $ pip install -r ./docs/requirements.txt ``` 3. Exporting loaded COCO weights as TF checkpoint(`yolov3.ckpt`) and frozen graph (`yolov3_gpu_nms.pb`) . If you don't have [yolov3.weights]( Download and put it in the dir `./checkpoint` ```bashrc $ python --convert --freeze ``` 4. Then you will get some `.pb` files in the dir `./checkpoint`, and run the demo script ```bashrc $ python $ python # if use camera, set video_path = 0 ``` ![image](./docs/images/611_result.jpg) ## part 3. Train on your own dataset Three files are required as follows: - `dataset.txt`: ``` xxx/xxx.jpg 18.19 6.32 424.13 421.83 20 323.86 2.65 640.0 421.94 20 xxx/xxx.jpg 55.38 132.63 519.84 380.4 16 # image_path x_min y_min x_max y_max class_id x_min y_min ... class_id ``` - `anchors.txt` ``` 0.10,0.13, 0.16,0.30, 0.33,0.23, 0.40,0.61, 0.62,0.45, 0.69,0.59, 0.76,0.60, 0.86,0.68, 0.91,0.76 ``` - `class.names` ``` person bicycle car ... toothbrush ``` ### 3.1 Train raccoon dataset To help you understand my training process, I made this training-pipline demo. [raccoon dataset]( has only one class with 200 images (180 for train, 20 for test), I have prepared a shell script in the `./scripts` which enables you to get data and train it ! #### how to train it ? ``` $ sh scripts/ $ python # show your input image (optional) $ python # get prior anchors and rescale the values to the range [0,1] $ python --convert # get pretrained weights $ python $ tensorboard --logdir ./data ``` As you can see in the tensorboard, if your dataset is too small or you train for too long, the model starts to overfit and learn patterns from training data that does not generalize to the test data. #### how to test and evaluate it ? ``` $ python -cf ./checkpoint/yolov3.ckpt-2500 -nc 1 -ap ./data/raccoon_anchors.txt --freeze $ python $ python ``` if you are still unfamiliar with training pipline, you can join [here]( to discuss with us. |raccoon-181.jpg|raccoon-55.jpg| |---|:---:| |![weibo-logo](./docs/images/raccoon1.jpg)|![weibo-logo](./docs/images/raccoon2.jpg)| ### 3.2 Train other dataset Download VOC PASCAL trainval and test data ```bashrc $ wget $ wget $ wget ``` Download COCO trainval and test data ``` $ wget $ wget $ wget $ wget ``` ## part 4. Why it is so magical ? YOLO stands for You Only Look Once. It's an object detector that uses features learned by a deep convolutional neural network to detect an object. Although we has successfully run these codes, we must understand how YOLO works. ### 4.1 Anchors clustering The paper suggests to use clustering on bounding box shape to find the good anchor box specialization suited for the data. more details see [here]( ![image](./docs/images/K-means.png) ### 4.2 Architercutre details In this project, I use the pretrained weights, where we have 80 trained yolo classes (COCO dataset), for recognition. And the class [label](./data/coco.names) is represented as `c` and it's integer from 1 to 80, each number represents the class label accordingly. If `c=3`, then the classified object is a `car`. The image features learned by the deep convolutional layers are passed onto a classifier and regressor which makes the detection prediction.(coordinates of the bounding boxes, the class label.. etc).details also see in the below picture. (thanks [Levio]( for your great image!) ![image](./docs/images/levio.jpeg) ### 4.3 Neural network io: - **input** : [None, 416, 416, 3] - **output** : confidece of an object being present in the rectangle, list of rectangles position and sizes and classes of the objects begin detected. Each bounding box is represented by 6 numbers `(Rx, Ry, Rw, Rh, Pc, C1..Cn)` as explained above. In this case n=80, which means we have `c` as 80-dimensional vector, and the final size of representing the bounding box is 85.The first number `Pc` is the confidence of an project, The second four number `bx, by, bw, bh` represents the information of bounding boxes. The last 80 number each is the output probability of corresponding-index class. ### 4.4 Filtering with score threshold The output result may contain several rectangles that are false positives or overlap, if your input image size of `[416, 416, 3]`, you will get `(52X52+26X26+13X13)x3=10647` boxes since YOLO v3 totally uses 9 anchor boxes. (Three for each scale). So It is time to find a way to reduce them. The first attempt to reduce these rectangles is to filter them by score threshold. **Input arguments**: - `boxes`: tensor of shape [10647, 4] - `scores`: tensor of shape `[10647, 80]` containing the detection scores for 80 classes. - `score_thresh`: float value , then get rid of whose boxes with low score ``` # Step 1: Create a filtering mask based on "box_class_scores" by using "threshold". score_thresh=0.4 mask = tf.greater_equal(scores, tf.constant(score_thresh)) ``` ### 4.5 Do non-maximum suppression Even after yolo filtering by thresholding over, we still have a lot of overlapping boxes. Second approach and filtering is Non-Maximum suppression algorithm. * Discard all boxes with `Pc <= 0.4` * While there are any remaining boxes : * Pick the box with the largest `Pc` * Output that as a prediction * Discard any remaining boxes with `IOU>=0.5` with the box output in the previous step In tensorflow, we can simply implement non maximum suppression algorithm like this. more details see [here]( ``` for i in range(num_classes): tf.image.non_max_suppression(boxes, score[:,i], iou_threshold=0.5) ``` Non-max suppression uses the very important function called **"Intersection over Union"**, or IoU. Here is an exmaple of non maximum suppression algorithm: on input the aglorithm receive 4 overlapping bounding boxes, and the output returns only one ![image](./docs/images/iou.png) Welecome to discuss with me. ## part 5. Other Implementations [- **`YOLO
    • 目标识别
    • 接触网目标识别.zip
    • adaboost目标识别
    • 目标识别
    • 基于LabVIEW实现的目标识别.zip
    • 基于高速DSP的实时运动目标识别跟踪系统
    • 语义分割和目标识别论文.zip
    • 几种目标识别算法.论文
      一篇论文,基于gabor遗传算法的红外图像识别,基于PCA 和图像匹配的飞机识别算法,基于插值算法的真实图像与计算机生成图像鉴别
    • 目标识别领域顶刊论文合集21篇
    • 舰船目标识别