#encoding:latin-1

from numpy import *
import textwrap

def read_pgm(path):
    fp = file(path,"rb")
    rr = lambda fp: fp.readline().strip()
    format = rr(fp)
    size = map(int, rr(fp).split())
    maxcol = int(rr(fp))

    if format=="P5":
        return fromfile(fp, dtype=uint8).reshape(size[1],size[0])

    elif format=="P2":
        data = map(int, fp.read().split())
        return array(data, dtype=uint8).reshape(size[1],size[0])

    raise Exception("Can not read '%s', format '%s' not implemented" \
                    % (path, format))

def save_pgm(path, img):
    """ 
        save image in pgm ascii-format, see 
        http://netpbm.sourceforge.net/doc/pgm.html
    """
    fp = file(path, "wb")
    fp.write("P2\n")
    fp.write("%d %d\n" % (img.shape[1], img.shape[0]))
    fp.write("255\n")
    scaled_image = require(255*img, uint8).T
    text = " ".join("%d" % v for v in scaled_image.flatten())
    print >> fp, "\n".join(textwrap.wrap(text, 68))