今天是阳历 2024 年 05 月 03 日 星期五 农历 三月月 廿五日

 

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Images

Creating Images

Image Formats | Creating Images | Changing Format | Transparent Backgrounds | Background Tiling | Animated GIFs | Image Resources | Screen Captures | Going Further

There are many excellent commercial products for creating graphics with computers running Windows. They are broadly divided into two groups: (1) painting programs and (2) drawing programs.

Painting Programs and Drawing Programs

Programs in the first category build up an image by assigning a color to every pixel of the screen that falls inside the boundaries of the image. Programs in the second category build up an image by assembling lines, arcs, etc. that are considered by the program to be distinct objects rather than just a set of unrelated pixels. Paint programs are generally easier to learn to use, but drawing programs can give higher quality results for many forms of graphics. Some programs combine both painting and drawing capabilities. The Windows accsessory Paint belongs to the first category; Freehand and Illustrator are professional level examples of the second.

Native Formats for Saved Images

In many cases programs save graphics images in their own "native" format that is specific to that one program. It is normally wise to save a version of the image in this format since it may be needed if you wish to modify the image later. However, in most instances, the native format for the graphics program cannot be directly displayed by Web browsers.

Exporting Other Image Formats

In addition to saving an image in native format, graphics programs usually also give you the option of saving the image in a format that can be used in other programs (but such saved files often cannot be further modified by the program you used to create the image). For example, as we noted earlier, many graphics programs for Windows allow you to save an image in BMP format.

Since you are then saving an image for use by another program, outside of the one that created the image, the process of saving a file in such a format is often referred to as "exporting" the image. Indeed, many graphics programs now have "Export Image", or some similar wording, as a separate item in their File menus. (Some programs also have a "Save for Web" item in this menu that will bring up a dialogue box with some special settings that you can configure for GIF and JPEG images.) In other cases, you can choose a non-native format by choosing "Save As" from the File menu and then selecting the desired format in the dialogue box that opens.

 

 
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