tailieunhanh - Photoshop cs5 by steve Johnson part 73

Tối ưu hóa một PNG-24 tài liệu Các PNG-24 định dạng tập tin được sử dụng chủ yếu cho hình ảnh có chứa rất nhiều màu sắc với các cạnh mềm chuyển đổi, chẳng hạn như hình ảnh, và được thiết kế như là một thay thế cho các định dạng file JPEG. Các định dạng PNG-24 tạo ra một hình ảnh với hàng triệu màu sắc, và vẫn quản lý để giảm bớt kích thước của tập tin. | Optimizing a PNG-24 Document The PNG-24 file format is used primarily for images that contain lots of colors with soft transitional edges such as photographs and was designed as an alternative to the JPEG file format. The PNG-24 format generates an image with millions of colors and still manages to reduce the size of a file. While similar to the JPEG file format the PNG-24 uses lossless compression and does not compress files as small as the JPEG format. So for the time being most designers are still using the JPEG format for creating faster-loading web graphics. Optimize a PNG-24 Document Open a document. Click the File menu and then click Save For Web Devices. Click the Original Optimized 2-Up or 4-Up tabs to view the document using different layouts. Click one of the sample images to change its default format. Click the Optimized File Format list arrow and then click PNG-24. Select from the following options Transparency Options Transparency. Check to keep the transparent areas of a PNG-24 image transparent. Matte. Click to fill the transparent areas of a PNG-24 image. Other Options Interlaced. Check to have the PNG-24 image load in three scans. Click Save to save the current image using the Save Optimized As dialog box. 456 Chapter 19 Optimizing a WBMP Document The WBMP file format is used for images that are displayed on small hand-held devices such as PDAs and cell phones. The WBMP format generates an image with only 2 pixel colors black and white which significantly reduces the file size of the image. The WBMP format is new to the world of wireless devices and while it creates small images using only black and white pixels results in very low-quality images. Optimize a WBMP Document Open a document. Click the File menu and then click Save For Web Devices. Click the Original Optimized 2-Up or 4-Up tabs to view the document using different layouts. Click one of the sample images to change its default format. Click the Optimized File Format list arrow and then