An essential technique you need to know about when you work with digital images is the use of transparency. Transparency allows you to cut out certain parts of an image to let what is underneath show through. In this video, author Richard Harrington explains what transparency is, how it is saved in a digital image, and how it can be used.
- You just saw an example of transparency in a graphic and this is a very common technique that's essential. Now there are some rudimentary tools inside of Power Point and Microsoft Word to add transparency data, but they're not as good as files that come with it built in. Transparency is going to allow you to store different types of pixels within the image. The transparency can be stored within the file formats. Now, something that is transparent is completely invisible.
Usually only part of a graphic is going to be fully transparent. For example, maybe the area around a logo. Partial transparency can also be used to create a translucent effect and you can do this within Office documents as well by adjusting the transparency settings. Not all applications will recognize or handle transparency data correctly however. This generally works by either having a specific color that's set to transparent or by using an embedded alpha channel.
In this case, I've taken a graphic that has partial transparency and you see as I animate that around the slide how we can see through it to the content down below. If you create graphics such as this, a PNG file, you can have elaborate levels of transparency to reveal data. Now, there are many different formats that support transparency. You can find it in bit map graphics, the GIF format, the newer JPEG 2000 which is gaining popularity on the web, PNG, which we've spent some time discussing already, and the tag image file format.
But what you need to realize is that some of these will not work with Office software. The BMP and the PNG graphics both should work quite well. The PNG being far more cross platform compatible than bit maps because the MAC platform doesn't like the BMP formats as much. While GIF files and TIFF files will work, GIF suffers from not very much information for color and detail. And TIFF files tend to be very large and might bog down your software or cause instability.
At this point the JPEG 2000 format has not been broadly supported by Microsoft but it is a file format that's catching on and one that you should pay attention to in case future support evolves. Now if you're working with vector graphics, which are very common for things like logos and illustrations, these usually have built in transparency as well. Most vector formats automatically support transparency because the vectors describe where to draw data and the other area is left empty.
So Adobe Illustrator and EPS files will have this built right in. If you're using the Windows metafile format this may also have it as well. Complex vector formats allow for transparency between the elements as well. This means that elements can be stacked or combined. You may encounter these inside of a PDF file for example. Or inside the SVG or scalable vector graphic format. When working in a computer software application transparency data is usually represented in a checkerboard pattern like this.
This is letting you know that this is the area where transparency data will show through. This is typically the canvas that you'll build on as you work with transparency data in programs like Photoshop, Illustrator or others.
- 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