#!/usr/bin/perl

$identify=      "/usr/local/ImageMagick/bin/identify";
$convert=       "/usr/local/ImageMagick/bin/convert";
$composite=     "/usr/local/ImageMagick/bin/composite";

$convdir=       "./pics";       #源路徑
$objcdir=       "./picd";       #目標路徑

$tmp=           "/tmp/.conv.tmp";
$white=         "/root/white.jpg";

opendir(OD,$convdir);
@allds=readdir OD;
closedir OD;

foreach $alldf(@allds){
        if($alldf ne "." && $alldf ne ".."){
                system("$convert $convdir/$alldf  -resize 100x100 $tmp");
                open(SO,"$identify $tmp|");
                $allso=<SO>;
                close SO;
                @alls=split(/ +/,$allso);
                @wh=split(/x/,$alls[2]);
                $wh[1]=~s//+[0-9]//g;
                if($wh[0]>$wh[1]){
                        $offset=(100-$wh[1])/2;
                        system("$composite -geometry +0+$offset $tmp $white $objcdir/$alldf");
                }else{
                        $offs=(100-$wh[0])/2;
                        system("$composite -geometry +$offset+0 $tmp $white $objcdir/$alldf");
                }
        }
}



這段程式碼的作用,是把"源路徑"裡的所有圖片,轉換成不大於100x100的縮圖片,然後加上背景(white.jpg),儲存在"目標路徑裡"
關鍵是 有這個：gif源圖縮小了還是動態的
convert 1-8-51-32-357532324.gif -resize 50x50 ysl.gif