What is the image resolution (pixel dimensions)?
The image is: 2048 × 1365 pixels @ 72 dpi
Digital images don't have any
dpi, or dots per inch. Pixels and dots are not the same things.
The
image resolution is 2048 pixels x 1356 pixels - a 3:2 aspect ratio.
To print 4 feet wide or 48" the
print resolution - pixels per inch (ppi) - would have to be set to:
2048 px / 48 " =
42.7 ppi. Insufficient print resolution to make a quality print 4 feet wide.
Unless the image resolution were to be increased quite a bit.
If it is a JPEG file, increasing the image resolution is likely to be problematic because the JPEG MMU (Minimum Coded Unit, a JPEG file compression technique) boundaries will likely become visible in the print.
Note: Image resolution
& print resolution determine print size.
Most print labs stake their reputations on about a 100 ppi minimum print resolution. In other words, they won't make a print at less than 100 ppi.
At 100 ppi the biggest your image file could print is: 2048 px / 100 ppi = 20.46 inches. A more realistic print resolution for a JPEG file is no less than 180 ppi.
At 180 ppi the print will be: 2048 px / 180 ppi = 11.2 inches wide.
So you need image resolution of at least 2048 px
times 2.34, or 4796 px on the long side. Call it 5000 px to print 4 feet wide. Having 4.2x, or 8633 px, would get you up to 180 ppi.