Hi Philip and Laurent. I've talked with Tilman and Andreas from the PDFBox team and they see similar connections to the ColorConvertOp filter but wanted to try with one of the images of the PDF as a raster.
As we try different things I thought it good for collaboration to create a repository with the code so all can contribute. https://github.com/kalaspuffar/ColorConvTest I've run the 3 different tests on my Machine (Thinkpad P51s) with custom Gentoo installed, if important to the conversation. I tried to invite you all as collaborators to this repository if you think this is a bad Idea let me know. Best regards Daniel On Wed, Oct 3, 2018 at 7:51 PM Laurent Bourgès <bourges.laur...@gmail.com> wrote: > Very good job, phil. > > I will try your CCONV test on my linux machine to see if it is platform > dependent ... or hw ? > > Laurent > > Le mer. 3 oct. 2018 à 19:19, Philip Race <philip.r...@oracle.com> a > écrit : > >> >> >> On 10/3/18, 1:15 AM, Laurent Bourgès wrote: >> >> Phil, >> >> If you look at the given pdf file, it has large images that exceed 2k so >> such ones may be more costly to convert. >> >> >> FWIW the one I profiled was by far the largest at 2577x1540. >> The rest are more like 100x100, 200x200 or 500x500 - all approximations. >> >> >> As jpeg decoder in openjdk11 is different than oraclejdk8, it may cause >> more ColorConvertOp filter operations ... if color profiles are different. >> >> >> That doesn't seem likely and in fact since I instrumented ColorConvertOp >> in 8 & 11, I know exactly how many times it was invoked >> by pdfbox, (11 times in both cases) and that all the image data is the >> same. SRC and DEST are the same types etc. >> >> Also the version of LCMS is the same in 8 and 11 (v2.9). >> >> -phil >> >> >> Anyway this performance is not related to Marlin renderer, so I can not >> help much except in its diagnostic. >> >> Cheers, >> Laurent >> >> Le mar. 2 oct. 2018 à 23:35, Philip Race <philip.r...@oracle.com> a >> écrit : >> >>> I've spent some time examining what pdfbox is passing to ColorConvertOp >>> It is called about 10 or 11 times in this test with images typically >>> 1-2K in each dimension. >>> The input image is a Custom BufferedImage which uses an ICC_ColorSpace >>> constructed >>> from a color profile file that is embedded in pdfbox which is an open >>> source equivalent >>> of what Acrobat uses. It has a 4 component raster and is opaque >>> >>> This is filtered into a 3 component standard INT_RGB ColorModel. >>> >>> I've distilled this down into a small program which has an copy of the >>> method >>> that is defined in pdfbox and is invoking the supposedly slow >>> ColorConvertOp. >>> >>> So I believe this is all exactly what is happening in pdfbox. >>> >>> What I find is that it is actually much faster on JDK11 than JDK 8. >>> >>> prrubuntu:~$ ~/jdk-11/bin/java CConv >>> 4881 >>> prrubuntu:~$ ~/jdk8u181/bin/java CConv >>> 12529 >>> >>> >>> I can't say why that would be but the results are clear. >>> So I am left to suppose that pdfbox really is doing something different >>> in 8 vs 11. >>> Or that this not the real problem. What do others see ? >>> >>> I've attached the program. The 1Mb color profile file can be got from >>> the pdfbox sources. >>> >>> -phil. >>> >>> >>> On 10/2/18, 9:35 AM, Laurent Bourgès wrote: >>> >>> Hi Daniel, >>> >>>> >>>> Let's not compare apples and oranges. What I can see it takes the same >>>> route and behave similarly. >>>> >>> >>> I agree, I did not take enough time to get accurate profiles, sorry. >>> >>> >>>> If you look at >>>> http://uhash.com/java_reg/Call_Tree_java_8.html >>>> http://uhash.com/java_reg/Call_Tree_java_11.html >>>> >>>> You can see that ConvertOp.filter takes 1.5s longer on Java 11. >>>> >>> >>> I confirm: 1.8s vs 300ms. >>> >>> Philip, do you know what could have change in this 2d area ? >>> >>> I imagine ColorConvertOp delegates to native code so color profile (ICC) >>> or hidpi support may have an impact here (or just compiler options may be >>> different) ... >>> >>> If needed, I could profile native code using oprofile / perf. >>> >>> Laurent >>> >>>
