blob: 872b89aa78136b3e89931436385291e1dcc33796 [file] [log] [blame] [edit]
# Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import heapq, logging
from PIL import Image
from PIL import ImageChops
from autotest_lib.client.cros.image_comparison import comparison_result
from autotest_lib.client.cros.video import method_logger
"""
*** Consider using PdiffImageComparer instead of this class ***
* This class uses pixel by pixel comparer while PdiffImageComparer encapsules
* the perceptualdiff tool available in ChromeOS
"""
class RGBImageComparer(object):
"""
Compares two RGB images using built-in python image library.
"""
def __init__(self, rgb_pixel_threshold):
self.pixel_threshold = rgb_pixel_threshold
@method_logger.log
def compare(self, golden_img_path, test_img_path, box=None):
"""
Compares a test image against a known golden image.
Both images must be RGB images.
@param golden_img_path: path, complete path to a golden image.
@param test_img_path: path, complete path to a test image.
@param box: int tuple, left, upper, right, lower pixel coordinates
defining a box region within which the comparison is made.
@return: int, number of pixels that are different.
"""
golden_image = Image.open(golden_img_path)
test_image = Image.open(test_img_path)
if golden_image.mode != 'RGB':
logging.debug('Golden image was not RGB. Converting to RGB.')
golden_image = golden_image.convert('RGB')
if test_image.mode != 'RGB':
logging.debug('Test image was not RGB. Converting to RGB.')
test_image = test_image.convert('RGB')
if box is not None:
golden_image = golden_image.crop(box)
test_image = test_image.crop(box)
diff_image = ImageChops.difference(golden_image, test_image)
maxcolors = diff_image.size[0] * diff_image.size[1]
colorstuples = diff_image.getcolors(maxcolors)
max_debug_count = 100
logging.debug("***ALL Color counts: %d", maxcolors)
logging.debug(heapq.nlargest(max_debug_count, colorstuples))
# getcolors returns a list of (count, color) tuples where count is the
# number of times the corresponding color in the image.
above_thres_tuples = [t for t in colorstuples
if any(pixel > self.pixel_threshold
for pixel in t[1])]
logging.debug("Color counts above thres.: %d", len(above_thres_tuples))
logging.debug(heapq.nlargest(max_debug_count, above_thres_tuples))
diff_pixels = sum(t[0] for t in above_thres_tuples)
return comparison_result.ComparisonResult(diff_pixels, '')
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
pass