Last weekend I drove down to Maryland to visit my parents. I parked my car, grabbed my bags out of the trunk, and before I could even get through the front door, my dad came out, excited and enlivened, exclaiming that he had just gotten back from the car dealership and traded in his old car for a brand new Honda Accord.
Most everyone enjoys getting a new car, but for my dad, who puts a lot of miles on his car each year for work, getting a new car is an especially big deal. In the Honda Accord models, a front camera sensor is mounted to the interior of the windshield behind the rearview mirror.
When I returned from visiting my parents I decided it would be fun and educational to write a tutorial on traffic sign recognition — you can use this code as a starting point for your own traffic sign recognition projects.
To learn more about traffic sign classification with Keras and Deep Learning, just keep reading! Traffic sign classification is the process of automatically recognizing traffic signs along the road, including speed limit signs, yield signs, merge signs, etc. Self-driving cars need traffic sign recognition in order to properly parse and understand the roadway. Traffic sign recognition is just one of the problems that computer vision and deep learning can solve.
There are a number of challenges in the GTSRB dataset, the first being that images are low resolutionand worse, have poor contrast as seen in Figure 2 above. Once downloaded, unzip the files on your machine. We will also walkthrough train. Our training script loads the data, compiles the model, trains, and outputs the serialized model and plot image to disk. From there, our prediction script generates annotated images for visual validation purposes. Instructions on how to create your virtual environment are included in the tutorial at this link.
This method as opposed to compiling from source simply checks prerequisites and places a precompiled binary that will work on most systems into your virtual environment site-packages. Optimizations may or may not be active.
Just keep in mind that the maintainer has elected not to include patented algorithms for fear of lawsuits.
Using Object Detection for Complex Image Classification Scenarios Part 4:
Sometimes on PyImageSearch, we use patented algorithms for educational and research purposes there are free alternatives that you can use commercially. If you need the full install, refer to my install tutorials page. If you are curious about 1 why we are using TensorFlow 2. Admittedly, the marriage of TensorFlow and Keras is built upon an interesting past. Once your environment is ready to go, it is time to work on recognizing traffic signs with Keras!
I have decided to name this classifier TrafficSignNet — open up the trafficsignnet. Our tf. Dropout is applied as a form of regularization which aims to prevent overfitting.
The result is often a more generalizable model. My Keras Tutorial also provides a brief overview. It accepts a path to the base of the dataset as well as a.
Line 28 loads our. Line 32 loops over the rows. Inside the loop, we proceed to:. We can automatically improve image contrast by applying an algorithm called Contrast Limited Adaptive Histogram Equalization CLAHEthe implementation of which can be found in the scikit-image library. Lines initialize the number of epochs to train for, our initial learning rate, and batch size.
Unnecessary markup in the file is automatically discarded. Lines initialize our data augmentation object with random rotation, zoom, shift, shear, and flip settings. At this point, you should be using TensorFlow 2. It seems counterintuitive to me. That said, all frameworks and codebases have certain nuances that we need to learn to deal with.
Note: Some class names have been shortened for readability in the terminal output block.This document describes an implementation of the RetinaNet object detection model. The code is available on GitHub. The instructions below assume you are already familiar with running a model on Cloud TPU. Use the pricing calculator to generate a cost estimate based on your projected usage. New Google Cloud users might be eligible for a free trial.
Open Cloud Shell. Configure the gcloud command-line tool to use the project where you want to create Cloud TPU. The configuration you specified appears. Enter y to approve or n to cancel. When the ctpu up command has finished executing, verify that your shell prompt has changed from username projectname to username vm-name. This change shows that you are now logged into your Compute Engine VM. This installs the required libraries and then runs the preprocessing script.
After you convert the data into TFRecords, copy them from local storage to your Cloud Storage bucket using the gsutil command. You must also copy the annotation files. These files help validate the model's performance:. Since you previously completed SSH key propagation, you can ignore this message. This tutorial requires a long-lived connection to the Compute Engine instance. To ensure you aren't disconnected from the instance, run the following command:. You are now ready to run the model on the preprocessed COCO data.
The following procedure uses the COCO evaluation data. It takes about 10 minutes to run through the evaluation steps. The fully supported RetinaNet model can work with the following Pod slices:. Run the ctpu up command, using the tpu-size parameter to specify the Pod slice you want to use. For example, the following command uses a v Pod slice. Cleaning up To avoid incurring charges to your Google Cloud Platform account for the resources used in this tutorial:.
Your prompt should now be username projectnameshowing you are in the Cloud Shell. The deletion might take several minutes.
Traffic Sign Classification with Keras and Deep Learning
A response like the one below indicates there are no more allocated instances:. Run gsutil as shown, replacing bucket-name with the name of the Cloud Storage bucket you created for this tutorial:. What's next Train with different image sizes You can explore using a larger neural network for example, ResNet instead of ResNet A larger input image and a more powerful neural network will yield a slower but more precise model.
Alternatively, you can explore pre-training a ResNet model on your own dataset and using it as a basis for your RetinaNet model. With some more work, you can also swap in an alternative neural network in place of ResNet. Finally, if you are interested in implementing your own object detection models, this network may be a good basis for further experimentation.
The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I am using the Retinanet model to train a classifier with about 50 classes.
The model is currently running and training with about 50 epochs and steps in each epoch. I see the losses going down and it should take about a day to finish the training. In general, output can be retrieved from the network as follows:. If by testing you mean running your own image through the network, have a look at the new example.
All it does is setup the environment, load in the model, load and prepare an image and visualize the results. Learn more. How to test your model on Retinanet? Ask Question. Asked 2 years, 2 months ago. Active 2 years, 1 month ago.
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Viewed 3k times. Create a csv of my images with the recommended format for reading. How do I proceed now with: a. Testing my model? Am I missing something? Again, sorry for the multi-fold questions and thank you for helping me out. Active Oldest Votes. Or is it not clear? Hans Gaiser Hans Gaiser 1 1 silver badge 4 4 bronze badges. I should have closed it.For tax assessments purposes, usually, surveys are conducted manually on the ground. These surveys are important to calculate the true value of properties.
For example, having a swimming pool can increase the property price. Similarly, the count of cars in a neighborhood or around a store can indicate the levels of economic activity at that place. Being able to achieve this through aerial imagery and AI, can significantly help in these processes by removing the inefficiencies, and the high cost and time required by humans.
I participated and secured the 3rd place in the public leaderboard with a mAP mean Average Precision of Pyramid networks have been used conventionally to identify objects at different scales.
The one-stage RetinaNet network architecture uses a Feature Pyramid Network FPN backbone on top of a feedforward ResNet architecture a to generate a rich, multi-scale convolutional feature pyramid b. To this backbone RetinaNet attaches two subnetworks, one for classifying anchor boxes c and one for regressing from anchor boxes to ground-truth object boxes d.
The network design is intentionally simple, which enables this work to focus on a novel focal loss function that eliminates the accuracy gap between our one-stage detector and state-of-the-art two-stage detectors like Faster R-CNN with FPN while running at faster speeds.
Focal Loss is an improvement on cross-entropy loss that helps to reduce the relative loss for well-classified examples and putting more focus on hard, misclassified examples. The focal loss enables training highly accurate dense object detectors in the presence of vast numbers of easy background examples. I am assuming you have your deep learning machine setup. If not, follow my guide here. Also, I would recommend using a virtual environment.
The following script will install RetinaNet and the other required packages. Alternatively, you can use a GPU instance p2.
This AMI comes pre-installed with keras-retinanet and other required packages. You can start using the model after activating the RetinaNet virtual environment by workon retinanet command. Note: Retinanet is heavy on computation.
Once the RetinaNet is installed, create the following directory structure for this project. You can ignore this if you are working on your own dataset and a different project.
First, we need to write a config file that will hold the paths to images, annotations, output CSVs — train, test, and classes, and the test-train split value. Having such a config file makes the code versatile for use with different datasets. It is a standard practice to have a 75—25 or a 70—30 or in some cases even 80—20 split between training and testing dataset from the original dataset.This document describes an implementation of the RetinaNet object detection model. The code is available on GitHub.
The instructions below assume you are already familiar with running a model on Cloud TPU. Use the pricing calculator to generate a cost estimate based on your projected usage. New Google Cloud users might be eligible for a free trial. Open Cloud Shell. Configure gcloud command-line tool to use the project where you want to create Cloud TPU. The configuration you specified appears. Enter y to approve or n to cancel.
When the ctpu up command has finished executing, verify that your shell prompt has changed from username projectname to username vm-name. This change shows that you are now logged into your Compute Engine VM. The COCO dataset will be stored on your Cloud Storage, so set a storage bucket variable specifying the name of the bucket you created:. This installs the required libraries and then runs the preprocessing script.
The COCO download and conversion script takes approximately 1 hour to complete. After you convert the data into TFRecords, copy them from local storage to your Cloud Storage bucket using the gsutil command. You must also copy the annotation files. These files help validate the model's performance.
Set the Cloud TPU name variable. This will either be a name you set with the --name parameter or the default, your username:. This tutorial requires a long-lived connection to the Compute Engine instance. To ensure you aren't disconnected from the instance, run the following command:. The following training scripts were run on a Cloud TPU v It will take more time, but you can also run them on a Cloud TPU vGitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together.
If nothing happens, download GitHub Desktop and try again. If nothing happens, download Xcode and try again. If nothing happens, download the GitHub extension for Visual Studio and try again. An example of testing the network can be seen in this Notebook. In general, inference of the network works as follows:. Where boxes are shaped None, None, 4 for x1, y1, x2, y2scores is shaped None, None classification score and labels is shaped None, None label corresponding to the score.
In all three outputs, the first dimension represents the shape and the second dimension indexes the list of detections. The training procedure of keras-retinanet works with training models. These are stripped down versions compared to the inference model and only contains the layers necessary for training regression and classification values.
If you wish to do inference on a model perform object detection on an imageyou need to convert the trained model to an inference model. This is done as follows:.
Most scripts like retinanet-evaluate also support converting on the fly, using the --convert-model argument. If you want to adjust the script for your own use outside of this repository, you will need to switch it to use absolute imports.
If you installed keras-retinanet correctly, the train script will be installed as retinanet-train. However, if you make local modifications to the keras-retinanet repository, you should run the script directly from the repository. That will ensure that your local changes will be used by the train script.
The default backbone is resnet The different options are defined by each model in their corresponding python scripts resnet. Trained models can't be used directly for inference. To convert a trained model to an inference model, check here. For training on Pascal VOCrun:. For training on a [custom dataset], a CSV file can be used as a way to pass the data. See below for more details on the format of these CSV files.
To train using your CSV, run:. All models can be downloaded from the releases page. Results using the cocoapi are shown below note: according to the paper, this configuration should achieve a mAP of 0. For more information, check ZFTurbo's repository. The CSVGenerator provides an easy way to define your own datasets. It uses two CSV files: one file containing annotations and one file containing a class name to ID mapping.
The CSV file with annotations should contain one annotation per line. Images with multiple bounding boxes should use one row per bounding box. Note that indexing for pixel values starts at 0. The expected format of each line is:. By default the CSV generator will look for images relative to the directory of the annotations file. Some images may not contain any labeled objects. This defines a dataset with 3 images. The class name to ID mapping file should contain one mapping per line.
Each line should use the following format:. In some cases, the default anchor configuration is not suitable for detecting objects in your dataset, for example, if your objects are smaller than the 32x32px size of the smallest anchors.Object Detection in Aerial Images is a challenging and interesting problem. By using Keras to train a RetinaNet model for object detection in aerial images, we can use it to extract valuable information.
With the cost of drones decreasing, there is a surge in amount of aerial data being generated. It will be very useful to have models that can extract valuable information from aerial data.
Retina Net is the most famous single stage detector and in this blog, I want to test it out on an aerial images of pedestrians and bikers from the Stanford Drone Data set. See a sample image below. This is a challenging problem since most objects are only a few pixels wide, some objects are occluded and objects in shade are even harder to detect.
Feature pyramid network is a structure for multiscale object detection introduced in this paper. It combines low-resolution, semantically strong features with high-resolution, semantically weak features via a top-down pathway and lateral connections. The net result is that it produces feature maps of different scale on multiple levels in the network which helps with both classifier and regressor networks. The Focal Loss is designed to address the single-stage object detection problems with the imbalance where there is a very large number of possible background classes and just a few foreground classes.
This causes training to be inefficient as most locations are easy negatives that contribute no useful signal and the massive amount of these negative examples overwhelm the training and reduces model performance. Focal loss is based on cross entropy loss as shown below and by adjusting the gamma parameter, we can reduce the loss contribution from well classified examples. In this blog, I want to talk about how to train a RetinaNet model on Keras.
I used this link to understand the model and would highly recommend it. My first trained model worked quite well in detecting objects aerially as shown in the video below. I have also open sourced the code on my Github link. Stanford Drone Data is a massive data set of aerial images collected by drone over the Stanford campus. The data set is ideal for object detection and tracking problems. It contains about 60 aerial videos.
To train the Retina Net, I used this implementation in Keras. It is very well documented and works without bugs. Thanks a lot to Fizyr for open sourcing their implementation!
The main steps I followed were:. I converted Stanford annotations in this format and my train and validation annotations are uploaded to my Github. So I adjusted the anchors to drop the biggest one of and instead add a small anchor of size This results in a noticeable improvement as shown below:.
With all this we are ready to start training.Training Custom Object Detector - TensorFlow Object Detection API Tutorial p.5
Here weights are the COCO weights that can be used to jump start training. The annotations for training and validation are the input data and config. All the files are on my Github repo too. The model is slow to train and I trained it overnight. I tested the accuracy of the trained model by checking for mean average precision MAP on the test set.
As can be seen below the first trained model had a very good MAP of 0. The performance is especially good on car and bus classes which are easy to see aerially. The MAP on Biker class is low as this is often confused by pedestrian. I am currently working on further improving accuracy of the Biker class. Retina Net is a powerful model that uses Feature Pyramid Networks.