名站导航为爱好php程序的朋友们提供php相关的教程知识。
php放大缩小图片，有需要的朋友可以参考下。
<?php
class image{
private $file;
private $image;
private $info;
public function __construct($file){
if(file_exists($file)){
$info = getimagesize($file);
$this->info = array(
'width' => $info[0],
'height' => $info[1],
'bits' => $info['bits'],
'mime' => $info['mime']
);
$this->image = $this->create($file);
}else{
exit("coulde not load image");
}
}
private function create($image){
$mime = $this->info['mime'];
if($mime == 'image/gif'){
return imagecreatefromgif($image);
}elseif($mime == 'image/png'){
return imagecreatefrompng($image);
}elseif($mime == 'image/jpeg'){
return imagecreatefromjpeg($image);
}
}
public function resize($width=0,$height=0,$default=''){
if (!$this->info['width'] || !$this->info['height']) {
return;
}
$xpos = 0;
$ypos = 0;
$scale = 1;
$scale_w = $width / $this->info['width'];
$scale_h = $height / $this->info['height'];
print_r($this->info);
if ($default == 'w') {
$scale = $scale_w;
} elseif ($default == 'h'){
$scale = $scale_h;
} else {
$scale = min($scale_w, $scale_h);
}
if ($scale == 1 && $scale_h == $scale_w && $this->info['mime'] != 'image/png') {
return;
}
$new_width = (int)($this->info['width'] * $scale);
$new_height = (int)($this->info['height'] * $scale);
$xpos = (int)(($width - $new_width) / 2);
$ypos = (int)(($height - $new_height) / 2);
$image_old = $this->image;
$this->image = imagecreatetruecolor($width, $height);//建立的是一幅大小为 x和 y的黑色图像(默认为黑色)
if (isset($this->info['mime']) && $this->info['mime'] == 'image/png') {
imagealphablending($this->image, false);//设定图像的混色模式
imagesavealpha($this->image, true);//设置标记以在保存PNG图像时保存完整的alpha通道信息www.mzdh.net
$background = imagecolorallocatealpha($this->image, 255, 255, 255, 127);//为一幅图像分配颜色 alpha
imagecolortransparent($this->image, $background);//将某个颜色定义为透明色
} else {
$background = imagecolorallocate($this->image, 255, 255, 255);//为一幅图像分配颜色
}
imagefilledrectangle($this->image, 0, 0, $width, $height, $background);//画一个矩形并填充
imagecopyresampled($this->image, $image_old, $xpos, $ypos, 0, 0, $new_width, $new_height, $this->info['width'], $this->info['height']);//重采样复制部分图像并调整大小
imagedestroy($image_old);
$this->info['width'] = $width;
$this->info['height'] = $height;
}
public function save($file,$quality = 90){
$info = pathinfo($file);
$extension = strtolower($info['extension']);
if (is_resource($this->image)) {
if ($extension == 'jpeg' || $extension == 'jpg') {
imagejpeg($this->image, $file, $quality);
} elseif($extension == 'png') {
imagepng($this->image, $file);
} elseif($extension == 'gif') {
imagegif($this->image, $file);
}
imagedestroy($this->image);
}
}
}
$root = $_SERVER['DOCUMENT_ROOT'].'/oimg/xts.jpg';
$newroot = $_SERVER['DOCUMENT_ROOT'].'/nimg/xts.jpg';
$image = new image($root);
$image->resize(50,10);
$image->save($newroot);
?>
好了关于php程序的知识就说到这里希望可以帮助需要的朋友。,微信大屏幕
