csv2Image.py

# Courtesy of Kaggle user 'NoBugs'
# Transforms string of numbers in .csv to image and saves it

import numpy as np
import cv2
import pandas as pd
import random
import os

curdir = os.path.abspath(os.path.dirname(__file__))

def gen_record(csvfile,channel):
    data = pd.read_csv(csvfile,delimiter=',',dtype='a')
    labels = np.array(data['emotion'],np.float)

    imagebuffer = np.array(data['pixels'])
    images = np.array([np.fromstring(image,np.uint8,sep=' ') for image in imagebuffer])
    del imagebuffer
    num_shape = int(np.sqrt(images.shape[-1]))
    images.shape = (images.shape[0],num_shape,num_shape)
    dirs = set(data['Usage'])
    subdirs = set(labels)
    class_dir = {}
    for dr in dirs:
        dest = os.path.join(curdir,dr)
        class_dir[dr] = dest
        if not os.path.exists(dest):
            os.mkdir(dest)

    data = zip(labels,images,data['Usage'])

    for d in data:
        label = int(d[0])
        if label == 1: # avoid disgust labels
            continue
        if label > 1: # avoid labels 0, 2, 3, 4, 5, 6,
            label -= 1
        destdir = os.path.join(class_dir[d[-1]],str(label))

        if not os.path.exists(destdir):
            os.mkdir(destdir)

        img = d[1]
        filepath = unique_name(destdir,d[-1])
        print('[^_^] Write image to %s' % filepath)

        if not filepath:
            continue

        sig = cv2.imwrite(filepath,img)
        if not sig:
            print('Error')
            exit(-1)


def unique_name(pardir,prefix,suffix='jpg'):
    filename = '{0}_{1}.{2}'.format(prefix,random.randint(1,10**8),suffix)
    filepath = os.path.join(pardir,filename)
    if not os.path.exists(filepath):
        return filepath
    unique_name(pardir,prefix,suffix)


if __name__ == '__main__':
    filename = './fer2013/fer2013.csv'
    filename = os.path.join(curdir,filename)
    gen_record(filename,1)