To perform object detection using ImageAI, all you need to do is
- Install Python on your computer system
- Install ImageAI and its dependencies
3. Download the Object Detection model file
4. Run the sample codes (which is as few as 10 lines)
Now let’s get started.
1) Download and install Python 3 from official Python Language website
2) Install the following dependencies via pip:
i. Tensorflow
pip install tensorflow
ii. Numpy
pip install numpy
iii. SciPy
pip install scipy
iv. OpenCV
pip install opencv-python
v. Pillow
pip install pillow
vi. Matplotlib
pip install matplotlib
vii. H5py
pip install h5py
viii. Keras
pip install keras
ix. ImageAI
pip installhttps://github.com/OlafenwaMoses/ImageAI/releases/download/2.0.1/imageai-2.0.1-py3-none-any.whl
3) Download the RetinaNet model file that will be used for object detection via this link.
Great. Now that you have installed the dependencies, you are ready to write your first object detection code. Create a Python file and give it a name (For example, FirstDetection.py), and then write the code below into it. Copy the RetinaNet model file and the image you want to detect to the folder that contains the python file.
FirstDetection.py
from imageai.Detection import ObjectDetection
import os
execution_path = os.getcwd()
detector = ObjectDetection()
detector.setModelTypeAsRetinaNet()
detector.setModelPath( os.path.join(execution_path , "resnet50_coco_best_v2.0.1.h5"))
detector.loadModel()
detections = detector.detectObjectsFromImage(input_image=os.path.join(execution_path , "image.jpg"), output_image_path=os.path.join(execution_path , "imagenew.jpg"))
for eachObject in detections:
print(eachObject["name"] + " : " + eachObject["percentage_probability"] )
Then run the code and wait while the results prints in the console. Once the result is printed to the console, go to the folder in which your FirstDetection.py is and you will find a new image saved. Take a look at a 2 image samples below and the new images saved after detection.
Before Detection:
Image Credit: alzheimers.co.uk
Image Credit: Wikicommons
After Detection:
Console result for above image:
person : 55.8402955532074
person : 53.21805477142334
person : 69.25139427185059
person : 76.41745209693909
bicycle : 80.30363917350769
person : 83.58567953109741
person : 89.06581997871399
truck : 63.10953497886658
person : 69.82483863830566
person : 77.11606621742249
bus : 98.00949096679688
truck : 84.02870297431946
car : 71.98476791381836
Console result for above image:
person : 71.10445499420166
person : 59.28672552108765
person : 59.61582064628601
person : 75.86382627487183
motorcycle : 60.1050078868866
bus : 99.39600229263306
car : 74.05484318733215
person : 67.31776595115662
person : 63.53200078010559
person : 78.2265305519104
person : 62.880998849868774
person : 72.93365597724915
person : 60.01397967338562
person : 81.05944991111755
motorcycle : 50.591760873794556
motorcycle : 58.719027042388916
person : 71.69321775436401
bicycle : 91.86570048332214
motorcycle : 85.38855314254761
Now let us explain how the 10-line code works.
from imageai.Detection import ObjectDetection import os execution_path = os.getcwd()
In the above 3 lines, we imported the ImageAI object detection class in the first line, imported the python os class in the second line and defined a variable to hold the path to the folder where our python file, RetinaNet model file and images are in the third line.
detector = ObjectDetection() detector.setModelTypeAsRetinaNet() detector.setModelPath( os.path.join(execution_path , "resnet50_coco_best_v2.0.1.h5")) detector.loadModel() detections = detector.detectObjectsFromImage(input_image=os.path.join(execution_path , "image.jpg"), output_image_path=os.path.join(execution_path , "imagenew.jpg"))
In the 5 lines of code above, we defined our object detection class in the first line, set the model type to RetinaNet in the second line, set the model path to the path of our RetinaNet model in the third line, load the model into the object detection class in the fourth line, then we called the detection function and parsed in the input image path and the output image path in the fifth line.
for eachObject in detections:
print(eachObject["name"] + " : " + eachObject["percentage_probability"] )
In the above 2 lines of code, we iterate over all the results returned by the detector.detectObjectsFromImage function in the first line, then print out the name and percentage probability of the model on each object detected in the image in the second line.
ImageAI supports many powerful customization of the object detection process. One of it is the ability to extract the image of each object detected in the image. By simply parsing the extra parameter extract_detected_objects=True into the detectObjectsFromImagefunction as seen below, the object detection class will create a folder for the image objects, extract each image, save each to the new folder created and return an extra array that contains the path to each of the images.
detections, extracted_images = detector.detectObjectsFromImage(input_image=os.path.join(execution_path , "image.jpg"), output_image_path=os.path.join(execution_path , "imagenew.jpg"), extract_detected_objects=True)