Getting Started with Mask Recognition Challenge
In this puzzle, we have detect mask type and bounding box of the mask from the image of human face.
In this notebook, we'll use the naive approach to prepare the baseline for this puzzle.
- We will create bounding box that will detect the face and crop the image as per the co-ordinates of bounding box from image.
- Once we've the cropped image(It'll have the image of mask), we'll feed the data to train classifier which will classify the mask.
So we will first need to download the python library by AIcrowd that will allow us to download the dataset by just inputting the API key.
%%capture !pip install aicrowd-cli %load_ext aicrowd.magic
Please login here: https://api.aicrowd.com/auth/24dM8PQYqbc2pXF9DN3V-k7To624IOvhM1jLreSiZxw API Key valid Gitlab access token valid Saved details successfully!
!rm -rf data !mkdir data %aicrowd ds dl -c mask-prediction -o data
!unzip data/train.zip -d data/ > /dev/null !unzip data/val.zip -d data/ > /dev/null !unzip data/test.zip -d data/ > /dev/null
#Reading the file import pandas as pd import numpy as np import os # Image Reading & Preprocessing from PIL import Image, ImageDraw import cv2 import matplotlib.pyplot as plt import numpy as np # Misc. from tqdm.notebook import tqdm from sklearn.ensemble import RandomForestClassifier
train_images = 'data/train' val_images = 'data/val' test_images = 'data/test'
train_df = pd.read_csv("data/train.csv") val_df = pd.read_csv("data/val.csv")
|0||k8o0f||[73, 197, 293, 400]||N95|
|1||7a0l9||[47, 364, 300, 512]||surgical|
|2||wfp7p||[203, 221, 380, 403]||N95|
|3||7qaw6||[87, 210, 322, 385]||surgical|
|4||i4kqj||[227, 283, 479, 475]||surgical|
train_df.loc[train_df.masktype == "cloth"][:2]
|5||uokc1||[3, 240, 276, 441]||cloth|
|13||qzbds||[91, 321, 380, 512]||cloth|
train_img = os.listdir(train_images) train_img[:5]
['urko1.jpg', 'ngb1h.jpg', 'u54pu.jpg', 'wvkoh.jpg', 'ou7fd.jpg']
From the above, we can see that ImageId is image_name without extensions(.jpg).
img = Image.open(os.path.join(train_images, '7a0l9.jpg')) img
In this section we are going to learn some opencv functions which can help us detecting the mask from the image!
# Converting the image to numpy array np_img= np.array(img) np_img.shape
(512, 512, 3)
# Converting the Image to RGB to Grayscale ( black/white ) gray= cv2.cvtColor(np_img, cv2.COLOR_BGR2GRAY) plt.imshow(gray)
<matplotlib.image.AxesImage at 0x7fed5dd8b850>
cv2.Canny is Canny Edge Detection which helps us to detect edges in the image. Let's try it our on the image
canny= cv2.Canny(gray, 120,250) plt.imshow(canny)
<matplotlib.image.AxesImage at 0x7fed5b845310>
So as you can see the function detected edges including the mask and some noise too, there are many ways to reduce that noise, however you can try changing the parameters in the function and see where that leads.
Contours are lines joining along the bounding of a intensity or color in an image. In the canny image or the original image, we see that the image has much different color as compared to the sky.
# Finding contours in the image contours, hierarchy = cv2.findContours(canny, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)
# Sorting the contours in ascending order contours = sorted(contours, key=cv2.contourArea)
# Getting the bounding boxes of the biggest contours x,y,w,h = list(cv2.boundingRect(contours[-1])) x,y,w,h
(47, 304, 253, 208)
# Showing the contour draw_img = img.copy() draw = ImageDraw.Draw(draw_img) draw.rectangle([x,y,x+w,y+h ], outline ="red") draw_img
So as you can see, fnding contours did a pretty great job in finfing the mask.
left,top,right, bottom = x,y,x+w,y+h
mask = img.crop((left,top,right, bottom)) mask