mapnik/tests/python_tests/png_encoding_test.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import sys
import os, mapnik
from timeit import Timer, time
from nose.tools import *
from utilities import execution_path, run_all

def setup():
    # All of the paths used are relative, if we run the tests
    # from another directory we need to chdir()
    os.chdir(execution_path('.'))

if mapnik.has_png():
    tmp_dir = '/tmp/mapnik-png/'
    if not os.path.exists(tmp_dir):
       os.makedirs(tmp_dir)

    opts = [
    'png',
    'png:t=0',
    'png8:m=o',
    'png8:m=o:c=1',
    'png8:m=o:t=0',
    'png8:m=o:c=1:t=0',
    'png8:m=o:t=1',
    'png8:m=o:t=2',
    'png8:m=h',
    'png8:m=h:c=1',
    'png8:m=h:t=0',
    'png8:m=h:c=1:t=0',
    'png8:m=h:t=1',
    'png8:m=h:t=2',
    ]

    # Todo - use itertools.product
    #z_opts = range(1,9+1)
    #t_opts = range(0,2+1)

    def gen_filepath(name,format):
        return os.path.join('images/support/encoding-opts',name+'-'+format.replace(":","+")+'.png')

    generate = False

    def test_expected_encodings():
        im = mapnik.Image(256,256)
        for opt in opts:
            expected = gen_filepath('solid',opt)
            actual = os.path.join(tmp_dir,os.path.basename(expected))
            if generate or not os.path.exists(expected):
              print 'generating expected image %s' % expected
              im.save(expected,opt)
            else:
              im.save(actual,opt)
            eq_(mapnik.Image.open(actual).tostring(),
                mapnik.Image.open(expected).tostring(),
                '%s (actual) not == to %s (expected)' % (actual,expected))

        for opt in opts:
            expected = gen_filepath('blank',opt)
            actual = os.path.join(tmp_dir,os.path.basename(expected))
            if generate or not os.path.exists(expected):
              print 'generating expected image %s' % expected
              im.save(expected,opt)
            else:
              im.save(actual,opt)
            eq_(mapnik.Image.open(actual).tostring(),
                mapnik.Image.open(expected).tostring(),
                '%s (actual) not == to %s (expected)' % (actual,expected))

    def test_transparency_levels():
        # create partial transparency image
        im = mapnik.Image(256,256)
        im.background = mapnik.Color('rgba(255,255,255,.5)')
        c2 = mapnik.Color('rgba(255,255,0,.2)')
        c3 = mapnik.Color('rgb(0,255,255)')
        for y in range(0,im.height()/2):
            for x in range(0,im.width()/2):
                im.set_pixel(x,y,c2)
        for y in range(im.height()/2,im.height()):
            for x in range(im.width()/2,im.width()):
                im.set_pixel(x,y,c3)

        t0 = tmp_dir + 'white0.png'
        t2 = tmp_dir + 'white2.png'
        t1 = tmp_dir + 'white1.png'

        # octree
        format = 'png8:m=o:t=0'
        im.save(t0,format)
        im_in = mapnik.Image.open(t0)
        t0_len = len(im_in.tostring(format))
        eq_(t0_len,len(mapnik.Image.open('images/support/transparency/white0.png').tostring(format)))
        format = 'png8:m=o:t=1'
        im.save(t1,format)
        im_in = mapnik.Image.open(t1)
        t1_len = len(im_in.tostring(format))
        eq_(len(im.tostring(format)),len(mapnik.Image.open('images/support/transparency/white1.png').tostring(format)))
        format = 'png8:m=o:t=2'
        im.save(t2,format)
        im_in = mapnik.Image.open(t2)
        t2_len = len(im_in.tostring(format))
        eq_(len(im.tostring(format)),len(mapnik.Image.open('images/support/transparency/white2.png').tostring(format)))

        eq_(t0_len < t1_len < t2_len,True)

        # hextree
        format = 'png8:m=h:t=0'
        im.save(t0,format)
        im_in = mapnik.Image.open(t0)
        t0_len = len(im_in.tostring(format))
        eq_(t0_len,len(mapnik.Image.open('images/support/transparency/white0.png').tostring(format)))
        format = 'png8:m=h:t=1'
        im.save(t1,format)
        im_in = mapnik.Image.open(t1)
        t1_len = len(im_in.tostring(format))
        eq_(len(im.tostring(format)),len(mapnik.Image.open('images/support/transparency/white1.png').tostring(format)))
        format = 'png8:m=h:t=2'
        im.save(t2,format)
        im_in = mapnik.Image.open(t2)
        t2_len = len(im_in.tostring(format))
        eq_(len(im.tostring(format)),len(mapnik.Image.open('images/support/transparency/white2.png').tostring(format)))

        eq_(t0_len < t1_len < t2_len,True)

    def test_transparency_levels_aerial():
        im = mapnik.Image.open('../data/images/12_654_1580.png')
        im_in = mapnik.Image.open('./images/support/transparency/aerial_rgba.png')
        eq_(len(im.tostring('png8')),len(im_in.tostring('png8')))
        eq_(len(im.tostring('png32')),len(im_in.tostring('png32')))

        im_in = mapnik.Image.open('./images/support/transparency/aerial_rgb.png')
        eq_(len(im.tostring('png32')),len(im_in.tostring('png32')))
        eq_(len(im.tostring('png32:t=0')),len(im_in.tostring('png32:t=0')))
        eq_(len(im.tostring('png32:t=0')) == len(im_in.tostring('png32')), False)
        eq_(len(im.tostring('png8')),len(im_in.tostring('png8')))
        eq_(len(im.tostring('png8:t=0')),len(im_in.tostring('png8:t=0')))
        # unlike png32 paletted images without alpha will look the same even if no alpha is forced
        eq_(len(im.tostring('png8:t=0')) == len(im_in.tostring('png8')), True)
        eq_(len(im.tostring('png8:t=0:m=o')) == len(im_in.tostring('png8:m=o')), True)

if __name__ == "__main__":
    setup()
    run_all(eval(x) for x in dir() if x.startswith("test_"))