Before you jump into the software and start to click buttons, there are a few pieces of technical knowledge that are important. These are things you will need to master so you can properly handle your digital images. In this video, author Richard Harrington discusses the technical knowledge you need for working with digital images.
- Before we jump into software and start clicking buttons, there are a few pieces of technical knowledge that are really important that you'll want to master so you can properly handle your digital images. The first one is going to be resolution. Now inside of Digital Images, we essentially use pixels. These are the digital building blocks that create digital images on screen. Now, computers and video devices use pixels to express information about an image.
Typically, each pixel is rendered as a square of light, and these are very small. They're difficult to see individually without magnification. Now the pixel is the smallest portion of the image that the computer is capable of displaying or printing. Essentially, think of this as like an atom in a cell. This is the smallest component that we have, and it leads to everything else. Now if you don't have enough pixels, the image is going to appear blocky, because there's not enough detail to work with.
However, if you have too many pixels, your computer can slow down dramatically because it has to process too much information. This can lead to instability, sluggish performance, or even an application crash. Alright, you've probably heard of pixels before, but where do pixels come from? Now the word pixel is actually a portmanteau. This is two words combined to make a new word. It takes the word picture and element and combines them for pixel. The word was first coined to describe the photographic elements on a television set.
This was done back in 1969 when writers for Variety Magazine, a popular magazine that covers the Hollywood industry, took the word pix, which was an abbreviation for pictures, and combined it with element to describe the TV signals that were coming together. Now some folks dispute the origin, and in fact, there are some records of NASA using it as well over in the Jet Propulsion Laboratory, which is a key part of their research area. So even though the exact origin may be slight disputed, the meaning is not.
The word pixel has really caught on. First in the scientific community, and then eventually in the computer industry during the 1980's. So, now that you know where pixels come from, how do they impact resolution? There are a lot of different terms used to describe it. Knowing the difference between them is important. Now the problem is that many people, and even technology companies, use the wrong terms when discussing them, and this leads to a lot of confusion. There are two major areas that you need to understand the difference, and they'll affect you when working with office software.
First off is dots per inch. Dots per inch is a printing term. This is used to describe the resolution for printed images. Now this is the most common one that you'll hear all the time. People will say dpi, and to determine dpi, essentially what happens is, someone counts the number of dots that physically fit within a one-inch by one-inch area. If you take a magnifying glass to many printed pieces, you can actually see the dots.
This is most visible on something like a newspaper. A higher dpi generally means smoother images, because the dots don't have to be as large, and there's more information used to describe image detail and color. But you'll see and hear dpi used a lot, but it only refers to print and physical output. So dpi is what you'll encounter the most, but most of the time, people are actually referring to onscreen documents, either viewing on a computer screen, or taking a look at something like a Power Point presentation.
In this case, we're actually dealing with pixels per inch or ppi. When you view images on a computer monitor, you are seeing pixels displayed on a screen. Originally, computer monitors use the concept of logical inches. This meant that the physical size of the computer display actually affected the resolution. So if you had a 12-inch monitor, it didn't have as much resolution as a 14-inch monitor. If you could afford a 20-inch monitor, it had a lot more.
Well, over time manufacturers starting realizing that people wanted the ability to adjust the resolution settings on their device based on personal taste. For example, when using a laptop, it's pretty common to adjust the settings based on your eyesight, or your need as you work. Originally, the MAC OS used 72 pixels per inch, and on the Windows side, they used 96 pixels per inch. These measurements are still important sometimes, because you'll often see things like Power Point documents expressed in inches, even though they're really not actually measured in inches any more.
So, as computer monitors evolved, they advanced to support variable resolution settings. You might be used to working with your computer and being able to adjust this. For example, here on Windows, if I right click on the desktop, I can choose my display settings. You'll notice if we scroll down, that we can see the resolution. For example, right now, I'm using a resolution of 1280 x 720, a smaller version of HD or High Definition.
That's pretty common for lots of folks to use. This of course can be adjusted, depending upon how you want to view the screen, or if you're plugged into an external monitor. You'll notice for example, that the computer can display both a 16 x 9 version, and a 4 x 3 version at that same resolution. Let's go ahead and close this, and you'll find similar settings available on a Mac computer as well. Simply go to your Apple menu and choose system preferences, and you'll see displays.
Now if you have an external display connected, you might be able to change the resolution directly, or you may notice that there are different settings available for your builtin display. You may find for example, simple presets to choose from, or the ability to target for your display connection. Now your computer may have slightly different settings available, but it's important that you know how to adjust those resolution settings to control output devices. For example, if you were to plug in a computer to something like a television or a projector to give your Power Point presentation, remember as computer monitors and displays have evolved, they've now support variable resolutions.
As such, the actual ppi for a screen can vary greatly, depending upon the physical size of the screen, the resolution being used by the computer graphics card, and other settings that you can choose within your software. There are settings that you need to be able to adjust, so make sure you take a look at the screen resolution settings on your PC, or that you explore the same settings on your Mac, so that you know how to get the correct display results for crisp images when working on presentation graphics.
Now that you understand resolution, from the computer's point of view, we can move on. A little later on, we'll talk about adjusting the settings inside of Microsoft Word and Power Point to control how they interpret resolution, and if they use the higher-quality files or create lower quality images when you import larger graphics. Now let's move on and talk a bit about color.
- Reviewing essential technological concepts
- Why does file format matter?
- JPG, PNG, and other raster formats
- Converting file formats with Adobe tools and free utilities
- Resizing images
- Matching visual style
- Adjusting the exposure, color, and size of an image
- Making essential image adjustments in Microsoft Word and PowerPoint
- Adjusting images with online image editors
- Adjusting images in a PDF file with Acrobat Pro
- Intellectual property rights