Ever been disappointed by a tiny printed image after editing a picture from your digital camera? Have you ever emailed a digital photo to your mother but the image file size was so big that her inbox rejected your attachment?
If you are just getting started with digital scrapbooking, then this short lesson is for you. It is a lot easier than you might guess.
Pixels and Resolution
The tiny dots that make up an image are called pixels. The word “pixel” is shorthand for picture element and generally is the smallest part of any type of digitally represented image. People are easily confused because the word pixel assumes subtle differences in meaning depending on the context in which it is used such as in printed images or the megapixels in a digital camera.
To simplify this discussion, just think of a pixel as a tiny point of light or color representing a very small component of a much larger image.
People also talk about resolution when referring to pixels. Resolution is the quantity of how many pixels fit into a certain defined space. You may have heard of “dots per inch” (DPI) or “pixels per inch” (PPI) and the meaning of these two terms adds to the confusion because once again it depends on the context in which the term is used.
Let’s simplify once again by saying that image resolution is an expression of how much detail an image holds.
Our televisions, computer displays, cell phones, and even digital photographs are full of pixels – thousands upon thousands of them all packed together so closely it tricks the human brain into thinking these tiny dots are a smooth image. These digital images appear just about anywhere we look in our technology filled world, from our PDAs to our car dashboard to the giant electronic billboards on display along the highway or in New York’s Times Square.
The more pixels inside an image, the smoother the photo looks. On the other hand, if the pixel count is too low, the image quality suffers. So you may be able to distinguish the individual dots in a microwave display but a printed digital photo looks as smooth as glass. When the pixel count is so low you can see the jagged edges, you’ve got a pixelated image.
Digital cameras have made sharing photos easier than ever. No longer do you have to get film developed and multiple copies printed. Today, many people share their photos through email and social network sites. However, before doing this the image taken from the digital camera is usually downsized.
Digital cameras are built to duplicate film camera quality and therefore capture images with a huge pixel resolution. Compare that to nearly all home computer screens that have a low pixel count, usually under 100 pixels in an inch. Displaying the former on the latter results in an image that appears much bigger on the computer screen. Digital cameras catch images at high resolution to permit photographic quality prints. But e-mailing this large image file will use megabytes of data and many e-mail users will disallow it.
Adjusting Resolution
The solution is to resample the image which is geek speak for altering the resolution. Decreasing the number of pixels will make the image appear normal on a computer screen. And this will let you e-mail Mom with the hottest family photos from your recent vacation. But after changing the resolution of the image, don’t think that you will still get a quality print any longer since you’ve taken out so many pixels.
So here is the fundamental point to remember. Digital images meant for printing need to be at a high resolution whereas images displayed on a computer screen need only a low resolution.
If you choose to do both of the above, make a copy of your original digital image for fiddling with. Besides preparing for both printing and viewing images correctly, this is also a highly recommended backup plan for all of your digital images.
Now that you know how pixel count affects digital images, you will enjoy complete success in printing and viewing any image you grab with your digital camera.
For a more thorough explanation of how to re-sample pictures and more topics on photo resolution, see Photoshop video tutorials at www.toNoodle.com.
