'''
Extract images from PDF without resampling or altering.

Adapted from work by Sylvain Pelissier
http://stackoverflow.com/questions/2693820/extract-images-from-pdf-without-resampling-in-python
'''

import sys
import PyPDF2
from PIL import Image

if (len(sys.argv) != 2):
    print("\nUsage: python {} input_file\n".format(sys.argv[0]))
    sys.exit(1)

pdf = sys.argv[1]

if __name__ == '__main__':
    input1 = PyPDF2.PdfFileReader(open(pdf, "rb"))
    page0 = input1.getPage(2)

    if '/XObject' in page0['/Resources']:
        xObject = page0['/Resources']['/XObject'].getObject()

        print(xObject)
        for obj in xObject:
            print(xObject[obj])
            if xObject[obj]['/Subtype'] == '/Image':
                size = (xObject[obj]['/Width'], xObject[obj]['/Height'])
                data = xObject[obj].getData()
                if xObject[obj]['/ColorSpace'] == '/DeviceRGB':
                    mode = "RGB"
                else:
                    mode = "P"
                
                if '/Filter' in xObject[obj]:
                    if xObject[obj]['/Filter'] == '/FlateDecode':
                        img = Image.frombytes(mode, size, data)
                        img.save(obj[1:] + ".png")
                    elif xObject[obj]['/Filter'] == '/DCTDecode':
                        img = open(obj[1:] + ".jpg", "wb")
                        img.write(data)
                        img.close()
                    elif xObject[obj]['/Filter'] == '/JPXDecode':
                        img = open(obj[1:] + ".jp2", "wb")
                        img.write(data)
                        img.close()
                else:
                    img = Image.frombytes(mode, size, data)
                    img.save(obj[1:] + ".png")
    else:
        print("No image found.")