Detailed explanation of PHP full-featured non-deformation image cropping operation classes and usage-PHP Tutorial-php.cn

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 the following

for details As follows:

If you need to crop pictures or generate thumbnails, there is basically no problem. All the required functions are inside, 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, and no padding if necessary. The generated picture will be 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 will be 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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