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Yihui Xie

2013-Oct-21 21:43 UTC

[Rd] png(type='cairo'): point symbols without boarders are not anti-aliased?

Hi,

It seems that anti-aliasing in png(type = 'cairo') is not well
supported for the point symbols without boarders, e.g. pch = 16. The
Cairo package works well, though. You can compare png() with
CairoPNG():

png(): http://i.imgur.com/8niB3jX.png
CairoPNG(): http://i.imgur.com/FZBJOxm.png

f = function(dev, ..., main = '') {
  dev(...)
  plot(c(1, 2, 1, 2), c(1, 1, 2, 2), pch=c(16, 19), cex=c(2, 2, 15, 15),
       xlim=c(0.5, 2.5), ylim=c(0.5, 3), main = deparse(substitute(dev)))
  dev.off()
}
f(grDevices::png, 'png-base.png', type = 'cairo')
f(Cairo::CairoPNG, 'png-Cairo.png')

If I remove the border for pch=19 (i.e. lwd=0), the point shows rough
edges as well.

I'm not sure if that is expected, or it is due to my misconfiguration
somewhere. I installed R via `apt-get install r-base-dev` under Ubuntu
using the CRAN repository.
> sessionInfo()R version 3.0.2 (2013-09-25)
Platform: x86_64-pc-linux-gnu (64-bit)

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
 [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
LC_PAPER=en_US.UTF-8       LC_NAME=C
 [9] LC_ADDRESS=C               LC_TELEPHONE=C
LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

loaded via a namespace (and not attached):
[1] Cairo_1.5-2 tools_3.0.2
> capabilities()    jpeg      png     tiff    tcltk      X11     aqua http/ftp  sockets
    TRUE     TRUE     TRUE     TRUE     TRUE    FALSE     TRUE     TRUE
  libxml     fifo   cledit    iconv      NLS  profmem    cairo
    TRUE     TRUE     TRUE     TRUE     TRUE     TRUE     TRUE


Regards,
Yihui
--
Yihui Xie <xieyihui at gmail.com>
Web: http://yihui.name
Department of Statistics, Iowa State University
2215 Snedecor Hall, Ames, IA

Yihui Xie

2013-Oct-21 21:44 UTC

head link

[Rd] png(type='cairo'): point symbols without boarders are not anti-aliased?

Sorry, typo in the subject: I mean "borders".

Regards,
Yihui
--
Yihui Xie <xieyihui at gmail.com>
Web: http://yihui.name
Department of Statistics, Iowa State University
2215 Snedecor Hall, Ames, IA


On Mon, Oct 21, 2013 at 4:43 PM, Yihui Xie <xie at yihui.name>
wrote:> Hi,
>
> It seems that anti-aliasing in png(type = 'cairo') is not well
> supported for the point symbols without boarders, e.g. pch = 16. The
> Cairo package works well, though. You can compare png() with
> CairoPNG():
>
> png(): http://i.imgur.com/8niB3jX.png
> CairoPNG(): http://i.imgur.com/FZBJOxm.png
>
> f = function(dev, ..., main = '') {
>   dev(...)
>   plot(c(1, 2, 1, 2), c(1, 1, 2, 2), pch=c(16, 19), cex=c(2, 2, 15, 15),
>        xlim=c(0.5, 2.5), ylim=c(0.5, 3), main = deparse(substitute(dev)))
>   dev.off()
> }
> f(grDevices::png, 'png-base.png', type = 'cairo')
> f(Cairo::CairoPNG, 'png-Cairo.png')
>
> If I remove the border for pch=19 (i.e. lwd=0), the point shows rough
> edges as well.
>
> I'm not sure if that is expected, or it is due to my misconfiguration
> somewhere. I installed R via `apt-get install r-base-dev` under Ubuntu
> using the CRAN repository.
>
>> sessionInfo()
> R version 3.0.2 (2013-09-25)
> Platform: x86_64-pc-linux-gnu (64-bit)
>
> locale:
>  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
> LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
>  [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
> LC_PAPER=en_US.UTF-8       LC_NAME=C
>  [9] LC_ADDRESS=C               LC_TELEPHONE=C
> LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
>
> loaded via a namespace (and not attached):
> [1] Cairo_1.5-2 tools_3.0.2
>
>> capabilities()
>     jpeg      png     tiff    tcltk      X11     aqua http/ftp  sockets
>     TRUE     TRUE     TRUE     TRUE     TRUE    FALSE     TRUE     TRUE
>   libxml     fifo   cledit    iconv      NLS  profmem    cairo
>     TRUE     TRUE     TRUE     TRUE     TRUE     TRUE     TRUE
>
>
> Regards,
> Yihui
> --
> Yihui Xie <xieyihui at gmail.com>
> Web: http://yihui.name
> Department of Statistics, Iowa State University
> 2215 Snedecor Hall, Ames, IA

Paul Murrell

2013-Oct-21 22:28 UTC

head link

[Rd] png(type='cairo'): point symbols without boarders are not anti-aliased?

Hi

Is this the same as "Bug 15462" ?
https://bugs.r-project.org/bugzilla3/show_bug.cgi?id=15462

Paul

On 10/22/13 10:43, Yihui Xie wrote:> Hi,
>
> It seems that anti-aliasing in png(type = 'cairo') is not well
> supported for the point symbols without boarders, e.g. pch = 16. The
> Cairo package works well, though. You can compare png() with
> CairoPNG():
>
> png(): http://i.imgur.com/8niB3jX.png
> CairoPNG(): http://i.imgur.com/FZBJOxm.png
>
> f = function(dev, ..., main = '') {
>    dev(...)
>    plot(c(1, 2, 1, 2), c(1, 1, 2, 2), pch=c(16, 19), cex=c(2, 2, 15, 15),
>         xlim=c(0.5, 2.5), ylim=c(0.5, 3), main = deparse(substitute(dev)))
>    dev.off()
> }
> f(grDevices::png, 'png-base.png', type = 'cairo')
> f(Cairo::CairoPNG, 'png-Cairo.png')
>
> If I remove the border for pch=19 (i.e. lwd=0), the point shows rough
> edges as well.
>
> I'm not sure if that is expected, or it is due to my misconfiguration
> somewhere. I installed R via `apt-get install r-base-dev` under Ubuntu
> using the CRAN repository.
>
>> sessionInfo()
> R version 3.0.2 (2013-09-25)
> Platform: x86_64-pc-linux-gnu (64-bit)
>
> locale:
>   [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
> LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
>   [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
> LC_PAPER=en_US.UTF-8       LC_NAME=C
>   [9] LC_ADDRESS=C               LC_TELEPHONE=C
> LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
>
> loaded via a namespace (and not attached):
> [1] Cairo_1.5-2 tools_3.0.2
>
>> capabilities()
>      jpeg      png     tiff    tcltk      X11     aqua http/ftp  sockets
>      TRUE     TRUE     TRUE     TRUE     TRUE    FALSE     TRUE     TRUE
>    libxml     fifo   cledit    iconv      NLS  profmem    cairo
>      TRUE     TRUE     TRUE     TRUE     TRUE     TRUE     TRUE
>
>
> Regards,
> Yihui
> --
> Yihui Xie <xieyihui at gmail.com>
> Web: http://yihui.name
> Department of Statistics, Iowa State University
> 2215 Snedecor Hall, Ames, IA
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>
-- 
Dr Paul Murrell
Department of Statistics
The University of Auckland
Private Bag 92019
Auckland
New Zealand
64 9 3737599 x85392
paul at stat.auckland.ac.nz
http://www.stat.auckland.ac.nz/~paul/

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