The three main terms used when discussing images are DPI, pixilation and resolution. Understanding these key terms is imperative when trying to enlarge or reduce the size of a picture. These terms are also widely used in digital media, graphic design, and more.
DPI, or dots per inch, is a measurement that is commonly used to show the amount of individual dots in a single square inch. DPI is also used to describe the amount of ink dots used to print an inch of an image. DPI is important when it comes to images because it relates to the density of pixels in an image. The higher the DPI the larger you’ll be able to reproduce the image without any sort of distortion. The same can be said of printing; the higher the DPI the greater the quality of the final print.
Pixilation refers to the distortion that occurs when an image is enlarged. When the individual pixels become evident to the naked eye, it is referred to as pixilation. Certain advanced software programs can be used to edit the image and reduce the pixilation. Beginning with an image with a higher DPI will reduce the likelihood of pixilation, though it is inevitable as the image get larger and larger.
Resolution refers to the number of individual pixels in the entire image. Similar to DPI, the higher the resolution of the original image, the higher the quality of any enlargements will be. The resolution of the image is the primary factor when considering at what point pixilation will occur.
To avoid pixilation, begin with an image that is high in resolution. Digital cameras are now able to take pictures in the thousands of pixels, referred to as megapixels. Always remember that the higher the megapixel resolution, the better when resizing and reprinting an image.