I might be losing it, but I am 99% sure that LCMS is the color
conversion engine in 8.
KCMS was there only for backup. You'd have to know the magic flag to get
it and
no one has said anything to the effect that they are using it.
-phil.
On 10/4/18, 11:33 AM, Laurent Bourgès wrote:
Phil,
I wondered if ang RenderingHint defaults changed since 8...
Moreover I started playing with linux perf + jit agent and it is easy
than before wigh oprofile + jvmtiagent.
I noticed that OracleJDK8 uses KCMS and OpenJDK11 uses LCMS for color
conversion as does OpenJDK8, that could explain the performance gap.
Finally PDFImage test is run only once so the overhead may come from
warmup (jit, g1)...
More later,
Laurent
Le jeu. 4 oct. 2018 à 20:03, Phil Race <philip.r...@oracle.com
<mailto:philip.r...@oracle.com>> a écrit :
On 10/03/2018 11:58 PM, Laurent Bourgès wrote:
Hi,
I will get the code and add debugging logs: env & system
properties and java2d RenderingHints.
The code in pdfbox passes null for the hints. So there should be
no difference attributable to that.
-phil.
I suspect these hints are different or have a noticiable impact:
color interpolation & rendering quality.
I suppose the backend corresponds to software loops but some 2d
operations can be accelerated ?
Anyway I will push any change in the code.
PS: I can run linux perf to profile both java & native code....
Cheers,
Laurent
Le jeu. 4 oct. 2018 à 07:50, Daniel Persson
<mailto.wo...@gmail.com <mailto:mailto.wo...@gmail.com>> a écrit :
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
<mailto: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 <mailto: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
<mailto: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
