https://bugs.kde.org/show_bug.cgi?id=408222
--- Comment #23 from Tobias Deiminger <haxti...@posteo.de> --- (In reply to Tobias Deiminger from comment #22) > $ compare -metric SSIM test-1-original.jpg test-1-cairo-200dpi.png null: 2>&1 > 0.826331 There was a mistake in the example. The compare tool needs two identical sized images (it works otherwise, but does a completely different thing then). So now I scale up poppler output back to original size with a high quality filter before comparing images. Here are some first test results: | Test conditions | avg. SSIM (higher is better) | orig_size new_size scale Splash Cairo Lanczos(*) 1894x2798 1799x2658 0.95 0.894696 0.97901 0.986598 1894x2798 1704x2518 0.90 0.940628 0.975257 0.961978 1894x2798 1609x2378 0.85 0.939805 0.972347 0.961621 1894x2798 1515x2238 0.80 0.896754 0.965689 0.972571 1894x2798 1420x2098 0.75 0.944005 0.955174 0.969092 1894x2798 1325x1958 0.70 0.944173 0.954734 0.966077 1894x2798 1231x1818 0.65 0.913747 0.959678 0.963164 1894x2798 1136x1678 0.60 0.932564 0.939862 0.959964 1894x2798 1041x1538 0.55 0.945498 0.926968 0.948855 1894x2798 947x1399 0.50 0.888512 0.951904 0.952485 1894x2798 852x1259 0.45 0.893747 0.944982 0.942065 1894x2798 757x1119 0.40 0.926194 0.938078 0.936967 1894x2798 6620x979 0.35 0.908621 0.928839 0.929847 1894x2798 568x 839 0.30 0.871821 0.9177 0.9235 1894x2798 473x 699 0.25 0.909859 0.903451 0.909088 1894x2798 378x 559 0.20 0.894681 0.88581 0.894793 1894x2798 284x 419 0.15 0.869878 0.879541 0.876719 1894x2798 189x 279 0.10 0.861054 0.858674 0.863767 If there were no further mistakes, that was a quite significant win for Cairo over Splash. I'm planning to publish my test methods and open an issue at poppler. There we can discuss if we take action. (*) Lanczos downsampling (with IM7) is included for reference and plausibility. -- You are receiving this mail because: You are watching all bug changes.
