Issues to Consider Before Constructing an Image


It's often quite tempting to just jump right in and start painting and drawing when creating a new image. However, if you stop for a moment and think about the image before you actually begin, you can save yourself time and possibly money.

Some things to consider include the overall size of the image (including its dimensions), the number of colors needed (which can affect the resulting file size), and the file size, especially if the image is intended for the Web.

Choosing an Image Size

Whether the image is intended for the Web, general onscreen viewing, or print media, the dimensions are among the first things to consider.

If your image is intended for onscreen presentation, you'll usually want it to fit within the limits of a computer screen.

More and more people are using 800x600 settings for their computer monitors . Some are even using much higher resolutions . Nevertheless, many people still run their screens at 640x480. If you know your audience well or are designing for a particular screen resolution, you're all set. If not, choose the resolution of your own screen or smaller.

With that decision out of the way, it's time to decide on the resolution in terms of dots per inch (dpi) or pixels per inch (ppi). If you're designing for onscreen or Web use, set the resolution to 72dpi, which is the norm for most computer screens. The differences you encounter won't be significant and, for onscreen use, the most important aspect to consider is width and height anyway.

If you'll be printing your image or having it printed, the dpi you choose will become a more important issue. If your final output is destined for print, you'll want to use a much higher resolution than that for onscreen presentations.

Most of today's printers are capable of 300x300, 600x600, or higher resolution, and sending a 72dpi image to one of those printers will result in either a much smaller image than you want or final print quality that's just not acceptable.

Be aware, though, that images with a higher resolution will be much larger. An image at 72dpi that's 4"x6" (which is about the standard size for prints you get back from most one- hour photo stores) is about 385KB uncompressed, whereas the same image at 300dpi takes up a whopping 6MB of hard drive space.

Keep in mind, too, that downsizing an image results in better quality than upsizing an image. If you take a small image and make it larger, you'll be disappointed with the results. If you take a larger image and make it smaller, though, the results, although not perfect, will be much better.

Choosing an Image Type

Another issue to consider is the image type, or number of colors (color resolution). If you're scanning an image into Paint Shop Pro, you should normally use the highest setting available ”especially for real-world images such as photographs. You should use a lower color setting when scanning in black-and-white art, though. If you're opening and working on an existing image, plan to stay with the existing color resolution.

graphics/bookpencil_icon.gif

Normally, your scanning software will adjust the number of colors based on the type of image it's scanning. You can still use a higher number of colors, especially if you apply effects to the image.

When you're finished working on the image, you can lower the number of colors if necessary. This change decreases the final file size and may even be necessary if you are saving to a file type such as GIF.

When you're starting a new image, you are faced with many color resolution options. This is when you have to decide on the image type. The image type you choose depends on the image you are creating and its intended purpose (such as the final output method).

Generally, you should start out with high color resolution, especially if you intend to use any of the special effects in Paint Shop Pro. Most of the effects are grayed out or otherwise not available when you work on lower color resolution images.

You can always change the image type after you complete the image. In fact, this step is necessary if you're working on an image with thousands or millions of colors that needs to be converted to a GIF file for the Web.

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I recommend keeping a copy of the original image in the higher color resolution in case you need to make changes later. This approach means that you won't have to change the color resolution over and over, which ultimately degrades an image's quality.

The choice for image type or number of colors is set when you open a new image. The New Image dialog box pops up when you choose File, New. You can set the width, height, and resolution. You also can set the background color and the image type. For image type, you can choose from the following options:

  • 2 Colors (1 Bit)

  • 16 Colors (4 Bit)

  • Grayscale (8 Bit)

  • 256 Colors (8 Bit)

  • 16.7 Million Colors (24 Bit)

You can also reset the color resolution by choosing Colors, Decrease Color Depth or Colors, Increase Color Depth. The Decrease Color Depth menu gives you more control than you get from the New File dialog box and the Increase Color Depth menu choice. From the Decrease Color Depth menu, you can also choose 32,000 colors, 64,000 colors, or an arbitrary number of colors for any image.

Normally, I start an image with 16.7 million colors so that I can effectively apply all the tools at my disposal. The image can always be downgraded to a lower color resolution when I'm done. That said, let's open a new image and explore a few of the available tools.



Sams Teach Yourself Internet and Web Basics All in One
Sams Teach Yourself Internet and Web Basics All in One
ISBN: 0672325330
EAN: 2147483647
Year: 2003
Pages: 350
Authors: Ned Snell

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