How Traditional Designers Make Web Images

With the development of the Internet, there are more and more Web image applications. It is the application of images that has enabled the WWW to enter a new era. A single text cannot be an effective method of information exchange. Images can give more visual vitality to a web page. Most graphic designers have been accustomed to processing images for prints. Although there is much in common between print image processing and web images, there are still significant differences between screen displays and print displays. If designers do not pay attention to these differences, it will affect the quality and normal display of Web images.

Resolution is a very important issue in the printing of images. The appropriateness of the resolution values ​​directly affects the quality of the printed matter. In web images, the value of the resolution is ignored and it will no longer work. No matter how much resolution you set for the image, the web browser will display the image pixels in one-to-one correspondence with the screen pixels (unless You set an additional image size in your HTML file.) This means that when dealing with Web images, all the dimensions you need to measure are the number of pixels, ie, how many pixels are wide and how many pixels are high. Some people suggest setting the web image pixels to 72dpi or 96dpi. There is nothing wrong with doing so, but there is no benefit.

As with printed images, there are not many file formats for Web image selection. Web images now support two file formats: GIF and JPEG. GIF is a format created by CompuServe to compress and transfer image files. Like the TIFF format, GIF uses LZW compression. However, unlike the TIFF format, the GIF format is limited to 256 colors. There are now two types of GIF format, represented by codes 87a and 89a. GIF87a strictly supports opaque pixels, while GIF89a allows certain pixels to be transparent. Before saving a GIF image with PHOTOSHOP, first use Image → Mode → Indexed Color to reduce the number of image colors to 256 or less. If the image exceeds 256 colors, the GIF format does not appear in the Save As pop-up menu. To save the background transparent GIF89a file, select File→Export→GIF89a Export. JPEG is a highly compressed format. JPEG format is a good choice when you need to save photos and other continuously changing images. Use it to save files that are smaller than any other format. However, because JPEG is a lossy compression scheme, large compression can affect image quality. Therefore, different compression ratios should be selected according to different requirements in the application.

All web images are RGB color modes (or a subset of index color or grayscale values). What you see on the screen is the resulting image. This eliminates the need for designers to convert images to CMYK colors. Mode and trouble. Also, most image processing software allows conversion between CMYK and RGB color modes. A CMYK TIFF image can be easily converted to an RGB JPEG image.

People on the Internet all have this experience, the smaller the image, the faster the opening will be. The term "small" here does not mean that the physical size is small (though it would be helpful to understand), but it means that it takes up less disk space. Downloading and displaying a 20K image of the same screen size is no doubt faster than processing a 50K image of a card size. Therefore, it is obviously not feasible to focus on the image quality just like a printed image. How to ensure the image quality requirements, and the file size can be controlled to be as small as possible, is the most important issue for Web graphic designers. Fortunately, image processing software vendors have paid attention to this issue, and the new version has enhanced support for Web images. Like FIREWORKS, which is tailor-made for the Web, its performance in this area is excellent.

Faced with the opportunities and challenges of the Internet, designers must not only use their traditional experience and advantages, but also fully understand the characteristics and technical requirements of new media and deepen their understanding of Web images. Only in this way can we use our talents in new fields to create more visual wealth for the society.