Re: Opacity issues with EPS

Hi Kyle,

EPS format and our older PS/PDF workstations do not support opacities.
 They should however not generate a SEGV, and if that's what you are
seeing, I should look into it. I will also file a feature request
ticket for an updated EPS driver that can make use of the new color
capabilities -- we *might* be able to slip that into the formal 6.1.0
release.

Apologies for the trouble...
Rick

On Wed, 12 Sep 2012 13:20:30 -0500
  Kyle Griffin <ksgriffin2@wisc.edu> wrote:
> Hi all,
>
> I've recently been working on a script in which I'm attempting to
>fill plot
> data overlaid above a couple of contour plots (one plain contours,
>one
> stipple-filled) and some polymarkers while also below some other
> polymarkers and several thousand polylines. However, it seems that
>the
> successful completion of this script depends on the cnFillType and
>one of
> the opacity levels chosen for the fill, and further the EPS output
>is
> sometimes corrupt/unreadable.
>
> In order to test which part of the resources/plotting was causing
>issues, I
> tried a number of scenarios, mainly changing the cnFillType and what
>kind
> of opacity settings were present. All of these test were output to
>EPS, as
> direct output to PNG seems to work fine. What I deduced is that
>RasterFill
> does not seem to handle any partial opacities when output to an EPS
> (RasterFill works fine with partial opacities when output to PNG),
>usually
> resulting in a seg fault at the 'draw' stage later in the script.
>CellFill
> seems to work fine with some opacity, and AreaFill, despite being
>time
> consuming with my data, plots things fine with partial opacities but
>NOT
> when plotting an item of 0 opacity to an EPS. The 0-level opacity
>seems to
> create something that image software ImageMagick and Ghostview can't
> process, despite the file size generally indicating that all the
>plotted
> information is within.
>
>For the record, I have been able to work around this with the
> higher-resolution PNG driver, but it would still be nice to have the
> complete transparency abilities with EPS as well.
>
> Although I'm not providing the complete script for now, I'll include
>the
> resources used in this troublesome plot, and highlight the ones that
>seem
> to play a role in creating the errors. In case the bolded plain text
>does
> not come through, those lines are re-pasted at the top of the text
>below.
>
> If my descriptions have been too vague, I can work up a sample
>script that
> will hopefully reproduce the problems. I may also be able to try and
>share
> the relevant data and script for those who would like to see it.
>Thanks,
>
>
> Kyle
>
> * **irres@cnFillMode = "AreaFill"*
>
> * colors(:,3) = 0.6** colors(0,3) = 0*
>
>
> irres = True
> irres@gsnDraw = False
> irres@gsnFrame = False
> irres@gsnLeftString = " "
> irres@gsnRightString = " "
> irres@cnInfoLabelOn = False
> irres@lbTitleFontHeightF = .009
> irres@lbLabelFontHeightF = .009* irres@cnFillMode = "AreaFill"* ;
> otherwise will take forever
> irres@gsnAddCyclic = False ; data already has cyclic
>point
>
> ;***********************************
> ; IR contour/fill irresources
> irres@lbBoxLinesOn = True
> irres@lbLabelBarOn = False
> irres@lbLabelStride = 4
> irres@pmLabelBarHeightF = 0.08
> irres@pmLabelBarOrthogonalPosF = 0.07
> irres@cnFillOn = True
> irres@gsnSpreadColors = True
> ; irres@gsnSpreadColorStart = 1
> ; irres@gsnSpreadColorEnd = 32
> irres@cnLinesOn = False
> irres@cnLineLabelsOn = False
> irres@cnLevelSelectionMode = "ManualLevels"
> irres@cnMinLevelValF = 190.
> irres@cnMaxLevelValF = 270.
> irres@cnLevelSpacingF = 2.5
>
> colors = spread_colors_rgba("WhiteBlueGreenYellowRed",0,252,irres)
> ; colors = spread_colors_rgba("grayscale_rgba",0,253,irres)*
> colors(:,3) = 0.6** colors(0,3) = 0*
> irres@cnFillColors = colors(::-1,:)
>
> ----------------------------------------
> Kyle S. Griffin
> Department of Atmospheric and Oceanic Sciences
> University of Wisconsin - Madison
> 1225 W Dayton St, Madison, WI 53706
> Room 1421 Email: ksgriffin2@wisc.edu

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Received on Wed Sep 12 12:42:12 2012