Php 图像大小调整png在背景中添加黑色
我正在使用下面的代码调整图像的大小,但它们的问题是,使用透明背景调整png图像的大小,因为它会用黑色填充背景 以下是图像大小调整的完整代码:Php 图像大小调整png在背景中添加黑色,php,image,image-resizing,Php,Image,Image Resizing,我正在使用下面的代码调整图像的大小,但它们的问题是,使用透明背景调整png图像的大小,因为它会用黑色填充背景 以下是图像大小调整的完整代码: function store_uploaded_image($html_element_name, $new_img_width, $new_img_height ,$size ,$target_dir) { $target_file = $target_dir .'image-'.$size.'.png'; $image =
function store_uploaded_image($html_element_name, $new_img_width, $new_img_height ,$size ,$target_dir) {
$target_file = $target_dir .'image-'.$size.'.png';
$image = new SimpleImage();
$image->load($_FILES[$html_element_name]['tmp_name']);
$image->resize($new_img_width, $new_img_height);
$image->save($target_file);
return $target_file; //return name of saved file in case you want to store it in you database or show confirmation message to user
}
class SimpleImage {
var $image;
var $image_type;
function load($filename) {
$image_info = getimagesize($filename);
$this->image_type = $image_info[2];
if( $this->image_type == IMAGETYPE_JPEG ) {
$this->image = imagecreatefromjpeg($filename);
} elseif( $this->image_type == IMAGETYPE_GIF ) {
$this->image = imagecreatefromgif($filename);
} elseif( $this->image_type == IMAGETYPE_PNG ) {
$this->image = imagecreatefrompng($filename);
}
}
function save($filename, $image_type=IMAGETYPE_PNG, $compression=75, $permissions=null) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image,$filename,$compression);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image,$filename);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image,$filename);
}
if( $permissions != null) {
chmod($filename,$permissions);
}
}
function output($image_type=IMAGETYPE_JPEG) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image);
}
}
function getWidth() {
return imagesx($this->image);
}
function getHeight() {
return imagesy($this->image);
}
function resizeToHeight($height) {
$ratio = $height / $this->getHeight();
$width = $this->getWidth() * $ratio;
$this->resize($width,$height);
}
function resizeToWidth($width) {
$ratio = $width / $this->getWidth();
$height = $this->getheight() * $ratio;
$this->resize($width,$height);
}
function scale($scale) {
$width = $this->getWidth() * $scale/100;
$height = $this->getheight() * $scale/100;
$this->resize($width,$height);
}
function resize($width,$height) {
$new_image = imagecreatetruecolor($width, $height);
imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
$this->image = $new_image;
}
}
编辑:
正如@Marc B所建议的,在imagecopyresampled
之前使用imagealpha混合
和imagesavealpha
,这项功能就开始工作了
imagealphablending( $targetImage, false );
imagesavealpha( $targetImage, true );
尝试先创建白色图像,然后将[“合并”]()与原始图像合并。您需要启用透明度选项,例如@MarcB working!感谢可能的副本