2011-11-22 61 views
3

我有以下用于从用户上传中生成缩略图的代码。 它使缩略图,保持宽高比和增加白色背景。 但它将其与左上方对齐。 我需要居中对齐,水平和垂直。需要居中缩放的缩略图

function makethumbnail($thumbw,$thumbh,$thumbName,$sourceName){ 

$ext=getExtension($sourceName); 
//echo $ext; 
$sourcePath = 'images/logos/deals/'; // Path of original image 
$sourceUrl = 'http://www.malldeals.com/admin/convert/'; 
$thumbPath = $sourcePath; // Writeable thumb path 
$thumbUrl = $sourceUrl . $thumbPath ; 
$thumbHeight=0; 
$thumbWidth=0; 
// Beyond this point is simply code. 
if(!strcmp("png",$ext)) 
    $sourceImage = imagecreatefrompng("$sourcePath/$sourceName"); 
else if(!strcmp("jpg",$ext) || !strcmp("jpeg",$ext)) 
    $sourceImage = imagecreatefromjpeg("$sourcePath/$sourceName"); 
else if(!strcmp("gif",$ext)) 
    $sourceImage = imagecreatefromgif("$sourcePath/$sourceName"); 
      global $sourceWidth, $sourceHeight; 
      $sourceWidth = imagesx($sourceImage); 
      $sourceHeight = imagesy($sourceImage); 

$ratio1=$sourceWidth/$thumbw; 
$ratio2=$sourceHeight/$thumbh; 
if($ratio1>$ratio2) { 
    $thumbWidth=$thumbw; 
    $thumbHeight=$sourceHeight/$ratio1; 
} 
else { 
    $thumbHeight=$thumbh; 
    $thumbWidth=$sourceWidth/$ratio2; 
} 


$targetImage = imagecreatetruecolor($thumbw,$thumbh); 

    // get the color white 
    $color = imagecolorallocate($targetImage, 255, 255, 255); 

    // fill entire image 
    imagefill($targetImage, 0, 0, $color); 
imagecopyresampled($targetImage,$sourceImage,0,0,0,0,$thumbWidth,$thumbHeight,imagesx($sourceImage),imagesy($sourceImage)); 

回答

1

像这样的东西可能会奏效,以取代上述

$offsetx = round((imagesx($sourceImage) - $thumbw)/2); 
$offsety = round((imagesy($sourceImage) - $thumbh)/2); 

imagecopyresampled($targetImage,$sourceImage,$offsetx,$offsety, 
0,0,$thumbWidth,$thumbHeight,imagesx($sourceImage),imagesy($sourceImage)); 
+0

这似乎并不奏效。请注意,我创建了两个缩略图,一个是180x60,另一个是50x50。上面的代码产生的结果是: original:(http://malldeals.com/admin/images/logos/1321988719ymca-ywca.jpg) thumbnail1:(http://malldeals.com/admin/images/logos /big1321988719ymca-ywca.jpg) thumbnail2:(http://malldeals.com/admin/images/logos/small1321988719ymca-ywca.jpg) –

1

我的PHP GD图像编辑做了一个函数的代码的最后一行
PHP-GD-Imagestyle
您可以使用自动调整大小创造中心的缩略图样式。

$thumb = imagestyle($image,'autosize:250 250');