php生成高清缩略图实例
php生成高清缩略图的方法,较为详细的分析了php生成缩略图时出现失真的解决方法,并给出了完整实例进行总结分析,需要的朋友可以参考下。
在使用php的函数生成缩略图的使用，缩略图很多情况下都会失真，这个时候需要有一些对应的解决方法。
1.用imagecreatetruecolor和imageCopyreSampled函数分别取代imagecreate和imagecopyresized
2.给imagejpeg的第三个参数带上100(例:imagejpeg($ni,$toFile,100))
下面是具体的函数
function CreateSmallImage( $OldImagePath, $NewImagePath, $NewWidth=154, $NewHeight=134)
{
/pic/2jpg/3png),3(width="638" height="340")
$OldImageInfo = getimagesize($OldImagePath);
if ( $OldImageInfo[2] == 1 ) $OldImg = @imagecreatefromgif($OldImagePath);
elseif ( $OldImageInfo[2] == 2 ) $OldImg = @imagecreatefromjpeg($OldImagePath);
else $OldImg = @imagecreatefrompng($OldImagePath);
/pic/p>
$NewImg = imagecreatetruecolor( $NewWidth, $NewHeight );
/pic/p>
$black = ImageColorAllocate( $NewImg, 0, 0, 0 ); /pic/p>
$white = ImageColorAllocate( $NewImg, 255, 255, 255 ); /pic/p>
$red = ImageColorAllocate( $NewImg, 255, 0, 0 ); /pic/p>
$blue = ImageColorAllocate( $NewImg, 0, 0, 255 ); /pic/p>
$other = ImageColorAllocate( $NewImg, 0, 255, 0 );
/pic/p>
$WriteNewWidth = $NewHeight*($OldImageInfo[0] / $OldImageInfo[1]); /pic/p>
$WriteNewHeight = $NewWidth*($OldImageInfo[1] / $OldImageInfo[0]); /pic/p>
/pic/p>
if ($OldImageInfo[0] / $NewWidth > $org_info[1] / $NewHeight) {
$WriteNewWidth = $NewWidth;
$WriteNewHeight = $NewWidth / ($OldImageInfo[0] / $OldImageInfo[1]);
} else {
$WriteNewWidth = $NewHeight * ($OldImageInfo[0] / $OldImageInfo[1]);
$WriteNewHeight = $NewHeight;
}
/pic/p>
if ( $WriteNewWidth <= $NewWidth ) {
$WriteNewWidth = $WriteNewWidth; /pic/p>
$WriteNewHeight = $NewHeight; /pic/p>
$WriteX = floor( ($NewWidth-$WriteNewWidth) / 2 ); /pic/p>
$WriteY = 0;
} else {
$WriteNewWidth = $NewWidth; /pic/p>
$WriteNewHeight = $WriteNewHeight; /pic/p>
$WriteX = 0;
$WriteY = floor( ($NewHeight-$WriteNewHeight) / 2 ); /pic/p>
}
/pic/p>
@imageCopyreSampled( $NewImg, $OldImg, $WriteX, $WriteY, 0, 0, $WriteNewWidth, $WriteNewHeight, $OldImageInfo[0], $OldImageInfo[1] );
/pic/p>
/pic/p>
@imagejpeg($NewImg, $NewImagePath, 100);
/pic/p>
@imagedestroy($NewImg);
}
CreateSmallImage("./images/jiexie.jpg","./images/jiexie.small.jpg",200,300);
CreateSmallImage("./images/jiexie.jpg","./images/jiexie.middle.jpg",400,500);
希望本文所述对大家php程序设计有所帮助。
【php生成高清缩略图实例】相关文章：
PHP生成缩略图的方法03-17
php上传图片生成缩略图02-17
PHP生成缩略图的类的方法10-14
php生成图片缩略图的方法11-16
php生成图片缩略图功能示例12-13
PHP生成器简单实例12-21
PHP生成图片缩略图类示例代码03-08
php生成缩略图的两种方法02-12