How to use imagecopyresampled (image processing function) in php?

How to use imagecopyresampled (image processing function) in php? The following article will explain in detail how to use the PHP image processing function imagecopyresampled. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

php image processing function imagecopyresampled usage

Syntax

bool imagecopyresampled ( resource $dst_image , resource $src_image , int $dst_x , int $dst_y , int $src_x , int $src_y , int $dst_w , int $dst_h , int $src_w , int $src_h )

Parameters:

dst_image	Target image connection resource.
src_image	Source image connection resource.
dst_x	Target X coordinate point.
dst_y	Target Y coordinate point.
src_x	The X coordinate point of the source.
src_y	The Y coordinate point of the source.
dst_w	Target width.
dst_h	Target height.
src_w	The width of the source image.
src_h	The height of the source image.

Returns TRUE on success, or FALSE on failure.

Case

1. Image cropping

<?php
  $targ_w = $targ_h = 150; // 设置目标宽度与高度
  $jpeg_quality = 90; // 图片质量90，满分为100
  $src = &#39;demo_files/pool.jpg&#39;; // 被处理的图片
  $img_r = imagecreatefromjpeg($src); // 获取原图
  $dst_r = ImageCreateTrueColor( $targ_w, $targ_h ); // 获取新图
  imagecopyresampled($dst_r,$img_r,0,0,$_POST[&#39;x&#39;],$_POST[&#39;y&#39;],
  $targ_w,$targ_h,$_POST[&#39;w&#39;],$_POST[&#39;h&#39;]); // 目标图 源图 目标X坐标点 目标Y坐标点 源的X坐标点 源的Y坐标点 目标宽度 目标高度 源图宽度 源图高度
  header(&#39;Content-type: image/jpeg&#39;);
  imagejpeg($dst_r,null,$jpeg_quality); // 输出图象到浏览器或文件
?>

2. Resampling

<?php
// 源文件
$filename = &#39;1.jpg&#39;;
// 设置最大宽高
$width = 400;
$height = 400;
// Content type
header(&#39;Content-Type: image/jpeg&#39;);
// 获取新尺寸
list($width_orig, $height_orig) = getimagesize($filename);
$ratio_orig = $width_orig/$height_orig;
if ($width/$height > $ratio_orig) {
  $width = $height*$ratio_orig;
} else {
  $height = $width/$ratio_orig;
}
// 重新取样
$image_p = imagecreatetruecolor($width, $height);
$image = imagecreatefromjpeg($filename);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
// 输出
imagejpeg($image_p, null, 100);
?>

Attached are three files of the uploaded image An idea

1. Select the picture, submit the form, the server handles the upload uniformly, save the path

2. Select the picture, upload, get the path, Submit the form, save the path

3. Select the image, upload it to the server, obtain the image from the server through some means, and save it locally
   

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