Graphics Programs Reference
In-Depth Information
Overview
Resizing
refers to changing the physical size of an image. In some cases, this will involve
discarding or creating pixels, but it can also refer to changing the height or width of an image
while maintaining the original number of pixels. We will talk about each of these situations
in this chapter.
If you have never resized an image, you might wonder why you need to know this. There
are many reasons for resizing.
1) If you want to use an image in a printed form — brochures, ads, book covers, pho-
tobooks, or art to adorn your walls — you will need to use an image resolution of at
least 300 ppi in most cases. For example, Amazon.com will not allow me to publish
my topics in print form unless every image is at least 300 ppi.
2) If you are sending an image over the Internet, it will typically have a resolution of 72
to 100 ppi in order to create a smaller file that is easier to send over the Internet.
3) If you are combining images, it is much easier if all the images have the same resol-
ution.
4) If you enter a photo contest, you will typically be required to submit your image at a
very specific size and resolution. For example — 2500 pixels on the longest side.
5) If you are selling prints of several different sizes, you will want to have an optimized
file for each size.
The fact is, resizing images is a very common and important task.
Chapter Four Video Lesson
