| # Copyright 2017 The PDFium Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| """Compares pairs of page images and generates an HTML to look at differences. |
| """ |
| |
| import functools |
| import glob |
| import multiprocessing |
| import os |
| import re |
| import subprocess |
| import sys |
| import webbrowser |
| |
| from common import DirectoryFinder |
| |
| |
| def GenerateOneDiffParallel(image_comparison, image): |
| return image_comparison.GenerateOneDiff(image) |
| |
| |
| class ImageComparison(object): |
| """Compares pairs of page images and generates an HTML to look at differences. |
| |
| The images are all assumed to have the same name and be in two directories: |
| [output_path]/[two_labels[0]] and [output_path]/[two_labels[1]]. For example, |
| if output_path is "/tmp/images" and two_labels is ("before", "after"), |
| images in /tmp/images/before will be compared to /tmp/images/after. The HTML |
| produced will be in /tmp/images/compare.html and have relative links to these |
| images, so /tmp/images is self-contained and can be moved around or shared. |
| """ |
| |
| def __init__(self, build_dir, output_path, two_labels, |
| num_workers, threshold_fraction): |
| """Constructor. |
| |
| Args: |
| build_dir: Path to the build directory. |
| output_path: Path with the pngs and where the html will be created. |
| two_labels: Tuple of two strings that name the subdirectories in |
| output_path containing the images. |
| num_workers: Number of worker threads to start. |
| threshold_fraction: Minimum percentage (0.0 to 1.0) of pixels below which |
| an image is considered to have only small changes. They will not be |
| displayed on the HTML, only listed. |
| """ |
| self.build_dir = build_dir |
| self.output_path = output_path |
| self.two_labels = two_labels |
| self.num_workers = num_workers |
| self.threshold = threshold_fraction * 100 |
| |
| def Run(self, open_in_browser): |
| """Runs the comparison and generates an HTML with the results. |
| |
| Returns: |
| Exit status. |
| """ |
| |
| if len(self.two_labels) != 2: |
| print >> sys.stderr, 'two_labels must be a tuple of length 2' |
| return 1 |
| |
| finder = DirectoryFinder(self.build_dir) |
| self.img_diff_bin = finder.ExecutablePath('pdfium_diff') |
| |
| html_path = os.path.join(self.output_path, 'compare.html') |
| |
| self.diff_path = os.path.join(self.output_path, 'diff') |
| if not os.path.exists(self.diff_path): |
| os.makedirs(self.diff_path) |
| |
| self.image_locations = ImageLocations( |
| self.output_path, self.diff_path, self.two_labels) |
| |
| difference = self._GenerateDiffs() |
| |
| small_changes = [] |
| |
| with open(html_path, 'w') as f: |
| f.write('<html><body>') |
| f.write('<table>') |
| for image in self.image_locations.Images(): |
| diff = difference[image] |
| if diff is None: |
| print >> sys.stderr, 'Failed to compare image %s' % image |
| elif diff > self.threshold: |
| self._WriteImageRows(f, image, diff) |
| else: |
| small_changes.append((image, diff)) |
| self._WriteSmallChanges(f, small_changes) |
| f.write('</table>') |
| f.write('</body></html>') |
| |
| if open_in_browser: |
| webbrowser.open(html_path) |
| |
| return 0 |
| |
| def _GenerateDiffs(self): |
| """Runs a diff over all pairs of page images, producing diff images. |
| |
| As a side effect, the diff images will be saved to [output_path]/diff |
| with the same image name. |
| |
| Returns: |
| A dict mapping image names to percentage of pixels changes. |
| """ |
| difference = {} |
| pool = multiprocessing.Pool(self.num_workers) |
| worker_func = functools.partial(GenerateOneDiffParallel, self) |
| |
| try: |
| # The timeout is a workaround for http://bugs.python.org/issue8296 |
| # which prevents KeyboardInterrupt from working. |
| one_year_in_seconds = 3600 * 24 * 365 |
| worker_results = (pool.map_async(worker_func, |
| self.image_locations.Images()) |
| .get(one_year_in_seconds)) |
| for worker_result in worker_results: |
| image, result = worker_result |
| difference[image] = result |
| except KeyboardInterrupt: |
| pool.terminate() |
| sys.exit(1) |
| else: |
| pool.close() |
| |
| pool.join() |
| |
| return difference |
| |
| def GenerateOneDiff(self, image): |
| """Runs a diff over one pair of images, producing a diff image. |
| |
| As a side effect, the diff image will be saved to [output_path]/diff |
| with the same image name. |
| |
| Args: |
| image: Page image to compare. |
| |
| Returns: |
| A tuple (image, diff), where image is the parameter and diff is the |
| percentage of pixels changed. |
| """ |
| try: |
| subprocess.check_output( |
| [self.img_diff_bin, |
| self.image_locations.Left(image), |
| self.image_locations.Right(image)]) |
| except subprocess.CalledProcessError as e: |
| percentage_change = float(re.findall(r'\d+\.\d+', e.output)[0]) |
| else: |
| return image, 0 |
| |
| try: |
| subprocess.check_output( |
| [self.img_diff_bin, |
| '--diff', |
| self.image_locations.Left(image), |
| self.image_locations.Right(image), |
| self.image_locations.Diff(image)]) |
| except subprocess.CalledProcessError as e: |
| return image, percentage_change |
| else: |
| print >> sys.stderr, 'Warning: Should have failed the previous diff.' |
| return image, 0 |
| |
| def _GetRelativePath(self, absolute_path): |
| return os.path.relpath(absolute_path, start=self.output_path) |
| |
| def _WriteImageRows(self, f, image, diff): |
| """Write table rows for a page image comparing its two versions. |
| |
| Args: |
| f: Open HTML file to write to. |
| image: Image file name. |
| diff: Percentage of different pixels. |
| """ |
| f.write('<tr><td colspan="2">') |
| f.write('%s (%.4f%% changed)' % (image, diff)) |
| f.write('</td></tr>') |
| |
| f.write('<tr>') |
| self._WritePageCompareTd( |
| f, |
| self._GetRelativePath(self.image_locations.Left(image)), |
| self._GetRelativePath(self.image_locations.Right(image))) |
| self._WritePageTd( |
| f, |
| self._GetRelativePath(self.image_locations.Diff(image))) |
| f.write('</tr>') |
| |
| def _WritePageTd(self, f, image_path): |
| """Write table column with a single image. |
| |
| Args: |
| f: Open HTML file to write to. |
| image_path: Path to image file. |
| """ |
| f.write('<td>') |
| f.write('<img src="%s">' % image_path) |
| f.write('</td>') |
| |
| def _WritePageCompareTd(self, f, normal_image_path, hover_image_path): |
| """Write table column for an image comparing its two versions. |
| |
| Args: |
| f: Open HTML file to write to. |
| normal_image_path: Path to image to be used in the "normal" state. |
| hover_image_path: Path to image to be used in the "hover" state. |
| """ |
| f.write('<td>') |
| f.write('<img src="%s" ' |
| 'onmouseover="this.src=\'%s\';" ' |
| 'onmouseout="this.src=\'%s\';">' % (normal_image_path, |
| hover_image_path, |
| normal_image_path)) |
| f.write('</td>') |
| |
| def _WriteSmallChanges(self, f, small_changes): |
| """Write table rows for all images considered to have only small changes. |
| |
| Args: |
| f: Open HTML file to write to. |
| small_changes: List of (image, change) tuples, where image is the page |
| image and change is the percentage of pixels changed. |
| """ |
| for image, change in small_changes: |
| f.write('<tr><td colspan="2">') |
| if not change: |
| f.write('No change for: %s' % image) |
| else: |
| f.write('Small change of %.4f%% for: %s' % (change, image)) |
| f.write('</td></tr>') |
| |
| |
| class ImageLocations(object): |
| """Contains the locations of input and output image files. |
| """ |
| |
| def __init__(self, output_path, diff_path, two_labels): |
| """Constructor. |
| |
| Args: |
| output_path: Path to directory with the pngs. |
| diff_path: Path to directory where the diffs will be generated. |
| two_labels: Tuple of two strings that name the subdirectories in |
| output_path containing the images. |
| """ |
| self.output_path = output_path |
| self.diff_path = diff_path |
| self.two_labels = two_labels |
| |
| self.left = self._FindImages(self.two_labels[0]) |
| self.right = self._FindImages(self.two_labels[1]) |
| |
| self.images = list(self.left.viewkeys() & self.right.viewkeys()) |
| |
| # Sort by pdf filename, then page number |
| def KeyFn(s): |
| pieces = s.rsplit('.', 2) |
| return (pieces[0], int(pieces[1])) |
| |
| self.images.sort(key=KeyFn) |
| self.diff = {image: os.path.join(self.diff_path, image) |
| for image in self.images} |
| |
| def _FindImages(self, label): |
| """Traverses a dir and builds a dict of all page images to compare in it. |
| |
| Args: |
| label: name of subdirectory of output_path to traverse. |
| |
| Returns: |
| Dict mapping page image names to the path of the image file. |
| """ |
| image_path_matcher = os.path.join(self.output_path, label, '*.*.png') |
| image_paths = glob.glob(image_path_matcher) |
| |
| image_dict = {os.path.split(image_path)[1]: image_path |
| for image_path in image_paths} |
| |
| return image_dict |
| |
| def Images(self): |
| """Returns a list of all page images present in both directories.""" |
| return self.images |
| |
| def Left(self, test_case): |
| """Returns the path for a page image in the first subdirectory.""" |
| return self.left[test_case] |
| |
| def Right(self, test_case): |
| """Returns the path for a page image in the second subdirectory.""" |
| return self.right[test_case] |
| |
| def Diff(self, test_case): |
| """Returns the path for a page diff image.""" |
| return self.diff[test_case] |
