ragg (version 0.1.1)

agg_tiff: Draw to a TIFF file

Description

The TIFF (Tagged Image File Format) format is a very versatile raster image storage format that supports 8 and 16bit colour mode, true transparency, as well as a range of other features not relevant to drawing from R (e.g. support for different colour spaces). The storage mode of the image data is not fixed and different compression modes are possible, in contrast to PNGs one-approach-fits-all. The default (uncompressed) will result in much larger files than PNG, and in general PNG is a better format for many of the graphic types produced in R. Still, TIFF has its purposes and sometimes this file format is explicetly requested.

Usage

agg_tiff(filename = "Rplot%03d.tiff", width = 480, height = 480,
  units = "px", pointsize = 12, background = "white", res = 72,
  compression = "none", bitsize = 8)

Arguments

filename

The name of the file. Follows the same semantics as the file naming in [grDevices::png()], meaning that you can provide a [sprintf()] compliant string format to name multiple plots (such as the default value)

width

The dimensions of the device

height

The dimensions of the device

units

The unit `width` and `height` is measured in, in either pixels (`'px'`), inches (`'in'`), millimeters (`'mm'`), or centimeter (`'cm'`).

pointsize

The default pointsize of the device in pt

background

The background colour of the device

res

The resolution of the device. This setting will govern how device dimensions given in inches, centimeters, or millimeters will be converted to pixels. Further, it will be used to scale text sizes and linewidths

compression

The compression type to use for the image data. The standard options from the [grDevices::tiff()] function are available under the same name.

bitsize

Should the device record colour as 8 or 16bit

Transparency

TIFF have support for true transparency, meaning that the pixel colour is stored in pre-multiplied form. This is in contrast to pixels being stored in plain format, where the alpha values more function as a mask. The utility of this is not always that important, but it is one of the benefits of TIFF over PNG so it should be noted.

Examples

# NOT RUN {
file <- tempfile(fileext = '.tiff')
# Use jpeg compression
agg_tiff(file, compression = 'lzw+p')
plot(sin, -pi, 2*pi)
dev.off()

# }