Digital Imaging Basics
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Introduction

Definitions of Terms

File Formats

Image Production

Image Size

Best Practices

Viewing File Info

Editing Images

File Management

Additional Resources

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Production of Digital Images

Digital images can be produced in a number of ways, the most common of which are detailed below.

Scanning: You can take pretty much any printed material and scan it to obtain a digital copy of it. Readily available scanners make scanning images on paper, printed photos, slides, and negatives a fairly simple process. Many of these scanners are "plug and play, " which means that soon after you unpack and plug your scanner into your computer, you can scan away without much delay.

Flatbed scanners (Figure 1) operate in a way similar to photocopier - you raise the lid, put the image face down on the glass, close the lid, and scan. Some of these flatbed scanners even have feeder trays, to quickly scan multiple pages.


Figure 1

Figure 2

Figure 3

Photo print, slide, and negative scanners (sometimes these are all combined into one scanner, as in Figure 2) usually have a slot into which you feed the item you want scanned. You can scan these types of materials on a flatbed scanner, but the raising and lowering of the lid often shifts or turns the items slightly, resulting in unexpectedly crooked or off-centered scans. Placing a small piece of tape across your item and the edge of the scanner - careful to avoid getting tape on the glass - can help to alleviate this problem.

Digital Cameras: Digital cameras (Figure 3) and camera phones are probably the fastest, easiest way to produce digital images. Keep in mind that there is quite a wide range of performance differences among brands, models by the same brand, and between consumer vs. professional grade equipment. What you really need to know is how to navigate through the function menu on your particular piece of equipment. The user manual will be very helpful in explaining what all those weird abbreviations, codes, and acronyms mean!

At this point, I want to point out a few notable settings on the digital camera:

1 - All digital cameras have variable settings for image quality, or "resolution." Some cameras have options such as "good," "better," and "best," while others actually have numbered pixel dimensions, such as 640x480 or 1600x1200. What it boils down to is this: the better the quality, or higher the numbers, the bigger the file size for each image, and the less total number of images you can fit on the memory card or disk. So, you have to decide, do you want fewer but higher-resolution pictures, or are you a shutterbug that needs to take 100 shots just to get a few that look good? Your situation and your skill may help determine this decision. Part of this includes your intended use of the pictures once you get them off the camera, which we will discuss in more detail later in this tutorial. If need be, you can purchase a memory card with larger storage capacity to hold more pictures.  

2 - Some digital cameras will let you choose which format you want your images saved in. All cameras will offer .JPG (or .JPEG) format, and some will offer .TIFF format (for high quality, high-resolution images). Additionally, some cameras may have a proprietary format option that only works with the software that came with the camera.

3 - Certain settings on your camera may return to default settings after turning the camera off. This can be especially annoying if you are trying to conserve the battery, but have to navigate through the menus and reset your desired quality or format settings each time you want to take a picture. Again, familiarity with these particular features on your camera will help a lot towards achieving better results.

Photo CDs: You may obtain a collection of digital images from your photo processor, along with your developed prints or slides. Many photo-processing services now provide photo CDs with .jpg images on them. If you are unfamiliar yet curious about the nature of these images, this tutorial should help you figure out what you can and can't do with them, and will give you suggestions for software that can help you manipulate or organize them.

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