The quality of the png output of vector plots is 'disappointing' (2.8.0)

[jypeter]

@doutriaux1 Maybe this has already been improved in the latest version...

I have generated pdf and png output, using the script in #185, and I hope you can improve the png rendering! The image below is a screendump of the pdf (displayed with Acrobat Pro) and the png (displayed with XnView), put side by side. png (on the right) is displayed at 100% and I have resized the pdf (on the left) to get roughly the same size

It looks as if the png image had been rendered in 2 color (B/W) without any anti-aliasing :( At least the data area of the plot. The text outside looks ok

Or is there something wrong with my setup (I'm using 2.8.0 on a remote server, to which I'm connected from a Linux running in VirtualBox) or this is linked to the black-png problem? The vectors look a bit nicer on https://uvcdat.llnl.gov/examples/Clim_JJA_850mb_rh_ts_gph.html, but I don't have the data to reproduce it on my machine (CDAT/cdat.github.io#137)

This is a bit frustrating, because I have been trying to make a good quality plot since yesterday and I ended up creating several issues. I would think that having user proof 2D vector plots comes before the streamlines :/

[durack1]

@jypeter thanks for continuing to generate these issues.. I have been using some of the nightly builds and many of my standing issues have been resolved.. Hopefully when the v2.10 lands soon you will also get access to the latest code base that @doutriaux1 @danlipsa and folks have been working on..

[doutriaux1]

@danlipsa opengl2 would help here?

[danlipsa]

@doutriaux1 It should. We should be able to do this with OpenGl1 as well. Its about turning antialiasing on when rendering and/or tracking why its not turned on if we already do that.

[durack1]

@danlipsa @doutriaux1 I'd be happy to provide some feedback in-house on this.. I always prefer to generate vector graphics as the default output format

[doutriaux1]

@danlipsa but antialiasing is on by default. So I'm not sure why @jypeter plots do not look too good.

[danlipsa]

@doutriaux1 That's what I thought as well. Looking at the plot it seems that the text is antialiased but the arrows are not. @jypeter @durack1 This is as if the png was saved with a certain resolution and then downsampled. How does a vector image look on the screen? What if the png is saved with the same resolution as the screen. Do you still have the problem?

[jypeter]

I'll try to remember checking that in 2.10 when I'm finished backing up my VM. If I can't do that before the bus leaves, and then I'm away till Monday