Home > Article > Backend Development > Introduction to the operation classes and usage of PHP full-featured image cropping without distortion
This article mainly introduces the full-featured non-deformation image cropping operation classes and usage of PHP, and analyzes the cropping, scaling and other related techniques of PHP operating images in the form of examples. Friends in need can refer to this article
The example describes the PHP full-featured image cropping operation class and usage without deformation. Share it with everyone for your reference, the details are as follows:
If you need to crop pictures or generate thumbnails, there is basically no problem with this. All the required functions are in it, and they are all non-deformable.
Here we divide it into four modes:
#1. Crop any picture to the specified size. If it exceeds the size, it will be cropped in the play. , and maximize the zoom, not enough stretching,
2. The excess is cropped in the play, but the insufficient is not stretched, that is, it is only reduced, not enlarged and cropped, which will produce filler, which can be eliminated with png transparency
3. Keep all image information. No cropping, just scaling, insufficient padding.
4. Keep all picture information. No cropping, only zooming, no padding if necessary, the generated picture is the actual effective pixel size, for example, if a picture is 600X600 and now you want to generate 120X100, then the actual effective pixels after scaling are 100X100, so only a 100X100 picture is generated, and the third This mode generates a size of 120X100, and has padding
The code is as follows (the code here is formatted through the online tool of this site http://tools.jb51.net/code/jb51_php_format) :
Crop(120,80,2);
* $ic->SaveImage();
* //$ic->SaveAlpha();将补白变成透明像素保存
* $ic->destory();
*
*
*/
class ImageCrop {
var $sImage;
var $dImage;
var $src_file;
var $dst_file;
var $src_width;
var $src_height;
var $src_ext;
var $src_type;
function ImageCrop($src_file,$dst_file='') {
$this->src_file=$src_file;
$this->dst_file=$dst_file;
$this->LoadImage();
}
function SetSrcFile($src_file) {
$this->src_file=$src_file;
}
function SetDstFile($dst_file) {
$this->dst_file=$dst_file;
}
function LoadImage() {
list($this->src_width, $this->src_height, $this->src_type) = getimagesize($this->src_file);
switch($this->src_type) {
case IMAGETYPE_JPEG :
$this->sImage=imagecreatefromjpeg($this->src_file);
$this->ext='jpg';
break;
case IMAGETYPE_PNG :
$this->sImage=imagecreatefrompng($this->src_file);
$this->ext='png';
break;
case IMAGETYPE_GIF :
$this->sImage=imagecreatefromgif($this->src_file);
$this->ext='gif';
break;
default:
exit();
}
}
function SaveImage($fileName='') {
$this->dst_file=$fileName ? $fileName : $this->dst_file;
switch($this->src_type) {
case IMAGETYPE_JPEG :
imagejpeg($this->dImage,$this->dst_file,100);
break;
case IMAGETYPE_PNG :
imagepng($this->dImage,$this->dst_file);
break;
case IMAGETYPE_GIF :
imagegif($this->dImage,$this->dst_file);
break;
default:
break;
}
}
function OutImage() {
switch($this->src_type) {
case IMAGETYPE_JPEG :
header('Content-type: image/jpeg');
imagejpeg($this->dImage);
break;
case IMAGETYPE_PNG :
header('Content-type: image/png');
imagepng($this->dImage);
break;
case IMAGETYPE_GIF :
header('Content-type: image/gif');
imagegif($this->dImage);
break;
default:
break;
}
}
function SaveAlpha($fileName='') {
$this->dst_file=$fileName ? $fileName . '.png' : $this->dst_file .'.png';
imagesavealpha($this->dImage, true);
imagepng($this->dImage,$this->dst_file);
}
function OutAlpha() {
imagesavealpha($this->dImage, true);
header('Content-type: image/png');
imagepng($this->dImage);
}
function destory() {
imagedestroy($this->sImage);
imagedestroy($this->dImage);
}
function Crop($dst_width,$dst_height,$mode=1,$dst_file='') {
if($dst_file) $this->dst_file=$dst_file;
$this->dImage = imagecreatetruecolor($dst_width,$dst_height);
$bg = imagecolorallocatealpha($this->dImage,255,255,255,127);
imagefill($this->dImage, 0, 0, $bg);
imagecolortransparent($this->dImage,$bg);
$ratio_w=1.0 * $dst_width / $this->src_width;
$ratio_h=1.0 * $dst_height / $this->src_height;
$ratio=1.0;
switch($mode) {
case 1: // always crop
if( ($ratio_w < 1 && $ratio_h < 1) || ($ratio_w > 1 && $ratio_h > 1)) {
$ratio = $ratio_w < $ratio_h ? $ratio_h : $ratio_w;
$tmp_w = (int)($dst_width / $ratio);
$tmp_h = (int)($dst_height / $ratio);
$tmp_img=imagecreatetruecolor($tmp_w , $tmp_h);
$src_x = (int) (($this->src_width-$tmp_w)/2) ;
$src_y = (int) (($this->src_height-$tmp_h)/2) ;
imagecopy($tmp_img, $this->sImage, 0,0,$src_x,$src_y,$tmp_w,$tmp_h);
imagecopyresampled($this->dImage,$tmp_img,0,0,0,0,$dst_width,$dst_height,$tmp_w,$tmp_h);
imagedestroy($tmp_img);
} else {
$ratio = $ratio_w < $ratio_h ? $ratio_h : $ratio_w;
$tmp_w = (int)($this->src_width * $ratio);
$tmp_h = (int)($this->src_height * $ratio);
$tmp_img=imagecreatetruecolor($tmp_w ,$tmp_h);
imagecopyresampled($tmp_img,$this->sImage,0,0,0,0,$tmp_w,$tmp_h,$this->src_width,$this->src_height);
$src_x = (int)($tmp_w - $dst_width) / 2 ;
$src_y = (int)($tmp_h - $dst_height) / 2 ;
imagecopy($this->dImage, $tmp_img, 0,0,$src_x,$src_y,$dst_width,$dst_height);
imagedestroy($tmp_img);
}
break;
case 2: // only small
if($ratio_w < 1 && $ratio_h < 1) {
$ratio = $ratio_w < $ratio_h ? $ratio_h : $ratio_w;
$tmp_w = (int)($dst_width / $ratio);
$tmp_h = (int)($dst_height / $ratio);
$tmp_img=imagecreatetruecolor($tmp_w , $tmp_h);
$src_x = (int) ($this->src_width-$tmp_w)/2 ;
$src_y = (int) ($this->src_height-$tmp_h)/2 ;
imagecopy($tmp_img, $this->sImage, 0,0,$src_x,$src_y,$tmp_w,$tmp_h);
imagecopyresampled($this->dImage,$tmp_img,0,0,0,0,$dst_width,$dst_height,$tmp_w,$tmp_h);
imagedestroy($tmp_img);
} elseif($ratio_w > 1 && $ratio_h > 1) {
$dst_x = (int) abs($dst_width - $this->src_width) / 2 ;
$dst_y = (int) abs($dst_height -$this->src_height) / 2;
imagecopy($this->dImage, $this->sImage,$dst_x,$dst_y,0,0,$this->src_width,$this->src_height);
} else {
$src_x=0;
$dst_x=0;
$src_y=0;
$dst_y=0;
if(($dst_width - $this->src_width) < 0) {
$src_x = (int) ($this->src_width - $dst_width)/2;
$dst_x =0;
} else {
$src_x =0;
$dst_x = (int) ($dst_width - $this->src_width)/2;
}
if( ($dst_height -$this->src_height) < 0) {
$src_y = (int) ($this->src_height - $dst_height)/2;
$dst_y = 0;
} else {
$src_y = 0;
$dst_y = (int) ($dst_height - $this->src_height)/2;
}
imagecopy($this->dImage, $this->sImage,$dst_x,$dst_y,$src_x,$src_y,$this->src_width,$this->src_height);
}
break;
case 3: // keep all image size and create need size
if($ratio_w > 1 && $ratio_h > 1) {
$dst_x = (int)(abs($dst_width - $this->src_width )/2) ;
$dst_y = (int)(abs($dst_height- $this->src_height)/2) ;
imagecopy($this->dImage, $this->sImage, $dst_x,$dst_y,0,0,$this->src_width,$this->src_height);
} else {
$ratio = $ratio_w > $ratio_h ? $ratio_h : $ratio_w;
$tmp_w = (int)($this->src_width * $ratio);
$tmp_h = (int)($this->src_height * $ratio);
$tmp_img=imagecreatetruecolor($tmp_w ,$tmp_h);
imagecopyresampled($tmp_img,$this->sImage,0,0,0,0,$tmp_w,$tmp_h,$this->src_width,$this->src_height);
$dst_x = (int)(abs($tmp_w -$dst_width )/2) ;
$dst_y = (int)(abs($tmp_h -$dst_height)/2) ;
imagecopy($this->dImage, $tmp_img, $dst_x,$dst_y,0,0,$tmp_w,$tmp_h);
imagedestroy($tmp_img);
}
break;
case 4: // keep all image but create actually size
if($ratio_w > 1 && $ratio_h > 1) {
$this->dImage = imagecreatetruecolor($this->src_width,$this->src_height);
imagecopy($this->dImage, $this->sImage,0,0,0,0,$this->src_width,$this->src_height);
} else {
$ratio = $ratio_w > $ratio_h ? $ratio_h : $ratio_w;
$tmp_w = (int)($this->src_width * $ratio);
$tmp_h = (int)($this->src_height * $ratio);
$this->dImage = imagecreatetruecolor($tmp_w ,$tmp_h);
imagecopyresampled($this->dImage,$this->sImage,0,0,0,0,$tmp_w,$tmp_h,$this->src_width,$this->src_height);
}
break;
}
}
// end Crop
}
?>
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