[Rd] Bug in Acrobat Reader 7 (or R?) with translucent text

[Marc Schwartz]

On Thu, 2006-10-19 at 15:14 -0500, Kevin Wright wrote:
> My setup:  R 2.4.0, Windows 2000, Acrobat Reader 7.
> 
> When I create a .pdf with translucent colors, the translucency works
> correctly for points, but not for text.  Below is some R code that
> creates a .pdf with this phenomenon.
> 
> I was going to report this as a bug in R, but then I tried to view the
> pdf with a couple of other viewers and found that at least one of the
> viewers correctly displayed the file (with translucent text), so maybe
> it is a bug with Acrobat Reader.  It might be worth checking to see if
> colors for "text" are handled any differently than colors for "points"
> that might cause this problem.
> 
> Best,
> 
> Kevin Wright
> 
> 
> black <- rgb(0,0,0,.75)
> blue <- rgb(0, .2, 1, .75)
> red <- rgb(1,0,0,.75)
> pdf("pdfcols.pdf", version="1.4")
> set.seed(50)
> plot(.5,.5,type="n",xlim=c(0,1),ylim=c(0,1))
> points(runif(200),runif(200), col=black)
> points(runif(200),runif(200), col=blue)
> points(runif(200),runif(200), col=red)
> text(.1, .1, "This is red", col=red)
> text(.1, .1, "Also red", col=red)
> text(.2, .2, "This is blue", col=blue)
> text(.2, .2, "Also blue", col=blue)
> text(.3, .3, "This is black", col=black)
> text(.3, .3, "Also black", col=black)
> points(runif(200),runif(200), col=black)
> points(runif(200),runif(200), col=blue)
> points(runif(200),runif(200), col=red)
> dev.off()

I can confirm problems on FC5 using Reader 7.0.8. The text appears
opaque.

An easier to see plot example might be:

black <- rgb(0, 0, 0, .5)
blue <- rgb(0, .2, 1, .5)
red <- rgb(1, 0, 0, .5)
pdf("TL.pdf", version = "1.4")
plot(1, 1, type = "n")
text(1.01, 1, "XXXXXXX", cex = 5, col = black)
text(1.02, 1, "XXXXXXX", cex = 5, col = red)
text(1.03, 1, "XXXXXXX", cex = 5, col = blue)
dev.off()

Using the 'Document Viewer' application on FC5, which is Evince, and
xpdf, the text is clearly translucent.

It's a bug in Adobe, unless there is a setting in Reader that impacts
this. Reviewing and trying some (ie. CoolType, Smoothing, etc.), there
is nothing immediately apparent that effects the display.

PDF File attached.

HTH,

Marc Schwartz

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