image_type: Identify the type of an image using the magic value at the...

In readbitmap: Simple Unified Interface to Read Bitmap Images (BMP,JPEG,PNG,TIFF)

Description

Currently works for png, jpeg, BMP, and tiff images. Will seek to start of file if passed a connection. For details of magic values for files, see e.g. http://en.wikipedia.org/wiki/Magic_number_(programming)#Magic_numbers_in_files

Usage

image_type(source, Verbose = FALSE)

Arguments

source	Path to file or connection
Verbose	Whether to write a message to console on failure (Default FALSE)

Value

character value corresponding to standard file extension of image format (i.e. jpg, png, bmp, tif) or NA_character_ on failure.

Examples

jpegfile=system.file("img", "Rlogo.jpg", package="jpeg")
image_type(jpegfile)
jpeg_pretending_to_be_png=tempfile(fileext = '.png')
file.copy(jpegfile, jpeg_pretending_to_be_png)
image_type(jpeg_pretending_to_be_png)
unlink(jpeg_pretending_to_be_png)

Example output

[1] "jpg"
[1] TRUE
[1] "jpg"

readbitmap documentation built on May 1, 2019, 8:47 p.m.