如何处理缩略图问题,谢谢.GD好像不能处理JPG,GIF的...

luobutou

如何处理缩略图问题,谢谢.GD好像不能处理JPG,GIF的...

Qiang

>;>; 如何处理缩略图问题

我假设你的问题是如何把大图变成小图 ..

>;>; GD好像不能处理JPG,GIF的

好像 ?  你的程序贴出来看看.

GD 因为专利问题不支持 gif.. 但 jpg, png 都支持.

你可以使用 Image::Magick

apile

GD很早已前的版本支援gif....
但是現在還是支援gif..只是不支援動畫那一塊..
有人說他的gif其實是png檔..不是很清楚...

因為Unisys擁有LZW壓縮專利..所以他跟各大廠商要錢..
甚至曾經提出一張Gif要多少權利金..所以目前靜態的Gif檔
依然免費..但是動態的只要用到LZW的就要錢...

關於縮圖..你可以看看
Graphics Programming with Perl 這本書..
我上Manning買了電子書...
後來發現edonkey上面有一堆...

chapter 6  Graphics and the Web
page 101
6.5. image collections and thumbnails with  Image::Magic
Page 102
6.5.2 Thumbnails with GD

我試過GD做出來的縮圖比較醜...
Image::Magick在AIX上面我裝不起來..所以沒用過..

Qiang

记得 GD 已经取消了 gif 的支持. 到 GD 的manual page 里看了一下.

Version 1.6 features the following changes:

Support for 8-bit palette PNG images has been added. Support for GIF has been removed. This step was taken to completely avoid the legal controversy regarding the LZW compression algorithm used in GIF. Unisys holds a patent which is relevant to LZW compression. PNG is a superior image format in any case. Now that PNG is supported by both Microsoft Internet Explorer and Netscape (in their recent releases), we highly recommend that GD users upgrade in order to get well-compressed images in a format which is legally unemcumbered.

该可以认为 GD 1.6 之后已经没有 gif 支持了. 听说 Unisys 的 paten 过期了, 但在一些国家还没有.

"Yes, Unisys still holds a patent on the LZW compression algorithm in some countries. The best solution is to move to legally unencumbered, well-compressed, modern image formats such as PNG and JPEG as soon as possible."

我以前也做过 GD 的缩图, 图片质量确实不好. 不过 image::magick 的不错.

讲太多无关的了... i  will shut up.

deathcult

早期版本支持，
可以去找以前的版本。