Thanks everyone for getting a solution.
Brian's solution works for me too.
Thanks again!!
Wayne
-----Original Message-----
From: Prof Brian Ripley <rip...@stats.ox.ac.uk>
Date: Friday, June 12, 2020 at 3:00 AM
To: "Fox, John" <j...@mcmaster.ca>, Simon Urbanek <simon.urba...@r-project.org>
Cc: Wayne Oldford <rwoldf...@uwaterloo.ca>, "r-devel@r-project.org"
<r-devel@R-project.org>
Subject: Re: [Rd] tcltk image reading problem (on a mac?): [tcl] encountered an
unsupported criticial chunk type "eXIf"
On 12/06/2020 03:49, Fox, John wrote:
> Dear Simon,
>
>> On Jun 11, 2020, at 9:00 PM, Simon Urbanek <simon.urba...@r-project.org>
wrote:
>>
>> Wayne,
>>
>> that one is unrelated, but interesting - you can fix it with
>>
>> sudo install_name_tool -change \
>> /usr/local/lib:/opt/X11/lib/libtk8.6.dylib \
>> /usr/local/lib/libtk8.6.dylib \
>> /usr/local/bin/wish8.6
>>
>> There is a bug in tcltk with IDs on the libraries which I have
worked-around for R, but not for wish.
>>
>> Back to the original question - do you have any example of a file that
doesn't work so I could test? Exif chunks are fairly rare in PNG and are a more
late extension so I couldn't find any examples.
>
> The code in Wayne's original message (copied below) generated the
offending file:
>
> library(tcltk)
>
> fname <- "Rplot.png"
> png(filename = fname, width = 500, height = 500)
> hist(rnorm(20))
> dev.off()
>
> tkimage.create("photo", file = fname)
There are several png() devices for R. The default on macOS is to use
Quartz, and that depends on macOS system functions so might well have
changed with Mojave -> Catalina.
As a workaround, try e.g. png(type='cairo'). E.g.
fname <- file.path(tempdir(), "Rplot.png")
png(filename = fname, width = 500, height = 500, type="cairo")
hist(rnorm(20))
dev.off()
library(tcltk)
tkimage.create("photo", file = fname)
works for me on Catalina.
--
Brian D. Ripley, rip...@stats.ox.ac.uk
Emeritus Professor of Applied Statistics, University of Oxford
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