I am getting myself familiarized with FastAI library.
I would like to practice creating data bunch directly off PyTorch dataset.
My dataset : X = image Y = binary label (0 or 1)
My dataset and databunch
import os
import torch
import pandas as pd
from skimage import io, transform
import numpy as np
import matplotlib.pyplot as plt
from torch.utils.data import Dataset, DataLoader
from torchvision import transforms
import cv2
# plt.ion()
class HotOrNotDataset(Dataset):
def __init__(self, csv_file, img_root, transform=None):
self.ratings = pd.read_csv(csv_file)
self.img_root = img_root
self.transform = transform
self.c = 1
self.loss_func = BCEFlat()
def __len__(self):
return len(self.ratings)
def __getitem__(self, idx):
img_name = os.path.join(self.img_root,
self.ratings.iloc[idx]['Filename'])
image = cv2.imread(img_name)
image = image / 255.0
target = self.ratings.iloc[idx]['Hot']
## Tagret is 0 or 1
sample = (image, target)
if self.transform:
sample = self.transform(sample)
return sample
class ToTensor(object):
"""Convert ndarrays in sample to Tensors."""
def __call__(self, sample):
image, label = sample
image = image.transpose((2, 0, 1))
return (torch.from_numpy(image).float(), torch.from_numpy(np.array([label])).long())
class Normalize(object):
def __init__(self):
self.normalize = transforms.Normalize(mean=[0.485, 0.456, 0.406],
std=[0.229, 0.224, 0.225])
def __call__(self, x):
image, label = x
return (self.normalize(image), label)
dataset = HotOrNotDataset(csv_file='ratings.csv',
img_root="./SCUT-FBP5500_v2/Images",
transform=transforms.Compose([ToTensor(),Normalize()])
)
db = DataBunch.create(dataset, dataset)
Training with learner:
# Bare minimum learner
import torchvision.models as models
model=models.mobilenet_v2(pretrained=True, progress=True)
for param in model.parameters():
param.requires_grad = False
new_head = nn.Sequential(nn.Dropout(p=0.2,inplace=False),
nn.Linear(in_features=1280,out_features=1000,bias=True),
nn.ReLU(),
nn.Linear(in_features=1000,out_features=1,bias=True),
nn.Sigmoid())
model.classifier = new_head
learn = Learner(db, model, metrics=[accuracy])
learn.fit(1)
Got the error “Error: multi-target not supported at /pytorch/aten/src/THCUNN/generic/ClassNLLCriterion.cu:15”
What am I doing wrong here?
Is the problem with dataset & databunch creation or it is something else?
Appreciate your help and support