// 剪切图片
function cut_img($src_image, $out_image = null, int $new_width = null, int $new_height = null, $img_quality = 90)
{
// 输出地址
if (! $out_image)
$out_image = $src_image;
// 读取配置文件设置
if (! $new_width && ! $new_height)
return;
// 获取图片属性
list ($width, $height, $type, $attr) = getimagesize($src_image);
switch ($type) {
case 1:
$img = imagecreatefromgif($src_image);
break;
case 2:
$img = imagecreatefromjpeg($src_image);
break;
case 3:
$img = imagecreatefrompng($src_image);
break;
}
// 不限定是等比例缩放
if (! $new_width) {
$new_width = floor($width * ($new_height / $height));
}
if (! $new_height) {
$new_height = floor($height * ($new_width / $width));
}
// 创建画布
$new_img = imagecreatetruecolor($new_width, $new_height);
// 创建透明画布,避免黑色
if ($type == 1 || $type == 3) {
$color = imagecolorallocate($new_img, 255, 255, 255);
imagefill($new_img, 0, 0, $color);
imagecolortransparent($new_img, $color);
}
// 先缩放
$scale = max($new_width / $width, $new_height / $height);
$scale_width = floor($scale * $width);
$scale_height = floor($scale * $height);
$scale_img = imagecreatetruecolor($scale_width, $scale_height); // 创建画布
if(function_exists("ImageCopyResampled")) {
imagecopyresampled($scale_img, $img, 0, 0, 0, 0, $scale_width, $scale_height, $width, $height);
} else {
imagecopyresized($scale_img, $img, 0, 0, 0, 0, $scale_width, $scale_height, $width, $height);
}
//再裁剪
$start_x = ($scale_width - $new_width) / 2;
$start_y = ($scale_height - $new_height) / 2;
//拷贝剪切的图像数据到画板,生成剪切图像
imagecopy($new_img, $scale_img, 0, 0, $start_x, $start_y, $scale_width, $scale_height);
check_dir(dirname($out_image), true); // 检查输出目录
switch ($type) {
case 1:
imagegif($new_img, $out_image, $img_quality);
break;
case 2:
imagejpeg($new_img, $out_image, $img_quality);
break;
case 3:
imagepng($new_img, $out_image, $img_quality / 10); // $quality参数取值范围0-99 在php 5.1.2之后变更为0-9
break;
default:
imagejpeg($new_img, $out_image, $img_quality);
}
imagedestroy($new_img);
imagedestroy($img);
return true;
}
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