how to download and display an image from an URL in R?

Question

My goal is to download an image from an URL and then display it in R.

I got an URL and figured out how to download it. But the downloaded file can't be previewed because it is 'damaged, corrupted, or is too big'.

y = "http://upload.wikimedia.org/wikipedia/commons/5/5d/AaronEckhart10TIFF.jpg"
download.file(y, 'y.jpg')

I also tried

image('y.jpg')

in R, but the error message shows like:

Error in image.default("y.jpg") : argument must be matrix-like 

Any suggestions?

Answer 1

If I try your code it looks like the image is downloaded. However, when opened with windows image viewer it also says it is corrupt. The reason for this is that you don't have specified the mode in the download.file statement.

Try this:

download.file(y,'y.jpg', mode = 'wb')

For more info about the mode is see ?download.file

This way at least the file that you downloaded is working.

To view the image in R, have a look at

jj <- readJPEG("y.jpg",native=TRUE)
plot(0:1,0:1,type="n",ann=FALSE,axes=FALSE)
rasterImage(jj,0,0,1,1)

or how to read.jpeg in R 2.15 or Displaying images in R in version 3.1.0

Answer 2

this could work too here

library("jpeg")

library("png")

x <- "http://upload.wikimedia.org/wikipedia/commons/5/5d/AaronEckhart10TIFF.jpg"    

image_name<- readJPEG(getURLContent(x)) # for jpg

image_name<- readPNG(getURLContent(x)) # for png

Answer 3

下载图像后，您可以使用 base R 使用默认图像查看器程序打开文件，如下所示：

file.show(yourfilename)