背景图片的疑惑

   很多朋友都喜欢写些比较大气的话题，职业呀、前途呀、人生呀，感觉博客好像就是应该写这些东西的，但我实在是写不出那些，只会谈点鸡毛蒜皮的技术，当然更多的是表达自己的困惑 。
    今天想说这前台界面的设计，很多时候都要用到背景图片，我多数时候也只是用用现成的而已，至于它们为什么有那样的格式，比如gif/png都搞不太清，两者都有人用，具体什么时候该用哪种不清楚；至于那些神奇的图片怎么制做就更不知道了：一条细细的直线就可以做背景，我很想学，不知道他们是从哪里学来的；但回头一想又觉得有点不对，做图片貌似是美工干的活呀。。。
    欢迎有同感的朋友留言.

评论

3 楼 hyj1254 2009-12-24  

谢谢楼上两位

2 楼 Hooopo 2009-12-24  

这里有一些资料..

引用

Selection of the Thumbnail format

The format in which you save a thumbnail can make a big difference to its final size on disk and download speed for web pages. In this regard I recommend you study the summary of the various Common File Formats.
Specifically you should note...
JPEG compresses well and is lossy, but is designed for large real world images, not small thumbnails. It also does NOT allow any form of transparency. In summary, the format is good for large images, bad for thumbnails. Watch out for profiles (see next section).
While JPG is not recommended for thumbnails, for viewing images on the WWW it is recommended you use smaller 800x600 pixel image, at a much lower "-quality" percentage (say 50 or even 30%), though it will not look very good.
It has also been suggested that using "-sampling-factor 2x1" will also produce a smaller JPEG image size.
I do not recommend the full original image never be placed directly on the web, unless temporarily (at a referenced location) for a friend to download. Remember do not link to it, (even by directory indexing), and never for more than a day, or it may be Googled.
GIF works for simple small images, and compresses okay. It has a color limit of 256, but for small images this is rarely noticeable. It can also do cartoon like animations of images, not that that is needed for thumbnails, unless you really what to get fancy.
What is a problem is that the format only has Boolean (on/off) transparency, which makes for horrible looking borders on shaped images. The solutions to that is to design the thumbnail to only use Boolean transparency, or arrange it so it can only be used on a specific background color. For details see the examples on GIF's on a background color or pattern.
PNG is the modern ideal format for thumbnails. It has a good compression, and internal format styles. It is non-lossy, and can display all colors, and these days it is understood by almost all browsers, (though for Microsoft Internet Explorer, before v7, needs some java scripting added to web pages).
More importunately this format understands semi-transparent color, making shadows and edges sharp and clear, or faded and blurry as you wish. This format however does not do animations, though the related MNG format does. Very few browsers seem to support that format however.
For thumbnails you can reduce the size of the final image by reducing the depth and number of colors, as well as setting a higher "bzip" compression quality (first digit in "-quality") for your final thumbnail image.
For example, the following is suggested for small PNG thumbnails that does not involve transparency.

via：http://www.imagemagick.org/Usage/thumbnails/

1 楼 机器人 2009-12-24  

你说的图片很细的做背景，那是用ps在一张背景图中切出的一两个象素的小图片。