• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL

Chapter Nine. Sizing > Image Size

Image Size

Q1:How do I change an image to an exact size? When I go to Image Size to enter the dimensions of my original photo, I'll type in 4 inches for the Width and it will automatically change the Height. Then I go to Height to enter 6 inches, and it changes the Width to 5.53 inches. How do I get it to be 4x6" exactly?
A1: By default, the Width and Height in the Image>Image Size command are linked together so the image stays in proportion. That's why when you change the Width, the Height changes to a number that is “mathematically correct.” You could uncheck Constrain Proportions, but that would cause your image to be stretched out of proportion. It's best to stick with the size given to you by the Image Size command.
Q2:How do I know when to resample, and when not to?

A2: When the Resample Image checkbox is turned on, resolution is independent of the dimensions of the image. This is designed for situations when you want to lower the resolution of the file without changing the dimensions. For example, let's say you have an image that's approximately 5x7" at a resolution of 300 ppi, but now you want to print it on your inkjet at a resolution of 175 ppi. With Resample Image checked, change the Resolution to 175 ppi and the settings in the Document Size section do not change (so the Width and Height do not change). However, when the Resample Image checkbox is turned off, the resolution and the dimensions of the image are tied together, so if you change the Width, the Resolution and Height fields change and vice versa. Turn Resample Image off when you have a low-res file from a digital camera and want to resize it without losing quality. For example, your camera file is 28x21" at 72 ppi, but you need a higher resolution. Turn off Resample Image, change the Resolution to 300 ppi, and then the Width and Height will change, in this example to approximately 5x7".
Q3:What is interpolation?
A3: Interpolation is a process that “invents” new pixels based on nearby pixels. It is used when you try to increase an image's resolution without changing its physical size. Some people call interpolation “fake resolution” because the results are not as good as if you had scanned at a higher resolution. In general, I would avoid it if possible, with a couple of exceptions:
  1. If you are scanning (or have scanned) line art, interpolation does not seem to have as noticeable an effect.

  2. If the image does not have fine detail (e.g., a cloudy sky), then the lack of sharpness will not be as much of an issue.

Q4:How do I change the size of my image? I can't figure out how to convert a scanned 8.5x11" picture into a TV monitor-size image (640x480 pixels).

A4: The command you need to use is Image Size (found in the Image menu). This will open a dialog that shows your current document size. In the Pixel Dimensions section, you can change either the Width or Height to 640 or 480 (whichever makes more sense based on your starting size), and then the other measurement will automatically change. Also, for video you don't need more than 72 ppi, and that is also changed in this same dialog.
Q5:Why does my image print so much smaller than it looks onscreen? When I look at my image on the screen, it looks very large, but when I print it, it is much smaller. Why?
A5: When you view images onscreen, the resolution of the image is affecting the way it displays. For example, if you scanned a 3x3" photo at 300 ppi, it would look about four times larger onscreen, as the resolution of your monitor is 72 ppi. The image itself is still a 3" square, and that's how large it will print.

The higher resolution of the scan lets you zoom in and display the pixels at the full resolution onscreen, but the size you see onscreen is not the actual print size. Try looking under the View menu and selecting Print Size—that will show a good approximation of how large the image will print. Or, use File>Print with Preview for a preview of how your image will print.



Not a subscriber?

Start A Free Trial

  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint