This is a 1 x 1 inch image saved at 288 pixels per inch. It demonstrates the web browser standard of always displaying images at 72 pixels per inch regardless of the actual image resolution.
640 x 480 pixels (or about 9 x 7 inches at 72 pixels per inch) is a good size on the web. It shows the entire image on most monitors without scrolling, and it shows adequate detail for most images. To make an image saved at more than 72 pixels per inch be displayed at 9 x 7 inches, reduce the physical size of the image. To figure that out for a 9 x 7 inch image saved at 300 pixels per inch:
- first: divide your pixels per inch by 72 (eg, 300 / 72 = 4.17) to get the divisor for the next step
- then: divide the desired web image size in inches by that result (eg, 9 / 4.17 = 2.16, 7 / 4.17 = 1.68)
Thus, saving your 300 pixel per inch image at 2.16 x 1.68 inches will show it on the web at 9 x 7 inches.