Today I found out how to get an image file's dimensions from within Safari, and I thought I'd share. You'll need the
Debug menu enabled.
- Load the image into its own window (or tab). If the image is embedded in within a document, control- (or right-) click on it and choose "Open Image in New Window."
- Go to the Debug menu and select "Show View Tree." Option-click on the disclosure triangle next to the only visible line.
- The last row of the "Width" and "Height" columns should tell you the image's dimensions.
If all you need are the dimensions of a current image, this will save some time over the "drag to desktop, open in photo application" process.