examples/pytorch/MyDataset.py

from __future__ import print_function, division
import os
import torch
import pandas as pd
from skimage import io, transform
import matplotlib.pyplot as plt
from torch.utils.data import Dataset, DataLoader
from torchvision import transforms, utils

import cv2
import numpy as np
import ceph

class MyDataset(Dataset):
	def __init__(self, csv_file, root_dir):
		"""
		Args:
			csv_file (string): Path to the csv file with annotations.
			root_dir (string): Bucket with all the images, such as s3://faces/
		"""
		self.landmarks_frame = pd.read_csv(csv_file)
		self.root_dir = root_dir
		
	def __len__(self):
		return len(self.landmarks_frame)

	def __getitem__(self, idx):
		img_name = os.path.join(self.root_dir, self.landmarks_frame.iloc[idx, 0])
		s3client = ceph.S3Client()	
		value = s3client.get(img_name)
		if not value:
			"""
			Picture doesn't exist in ceph, your code here to handle error
			"""
			return None
		img_array = np.fromstring(value, np.uint8)
		# load image
		#img = cvb.img_from_bytes(value)

		
		string_data = img_array.tostring()
		#print(string_data)
		#print(value)
		#image = cv2.imdecode(img_array, cv2.CV_LOAD_IMAGE_COLOR)

		landmarks = self.landmarks_frame.iloc[idx, 1:].as_matrix()
		landmarks = landmarks.astype('float').reshape(-1, 2)
		sample = {'image': img_array, 'landmarks': landmarks}

		return sample, string_data