On 12 Jun 2020, at 19:00, Prof Brian Ripley <ripley at stats.ox.ac.uk> wrote:
On 12/06/2020 03:49, Fox, John wrote:
Dear Simon,
On Jun 11, 2020, at 9:00 PM, Simon Urbanek <simon.urbanek at 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, ripley at stats.ox.ac.uk
Emeritus Professor of Applied Statistics, University of Oxford