\Intervention\Image\ImageManagerStatic::make($_FILES['file']['tmp_name'])->save('upload.jpg');//file为上传表单的name名
\Intervention\Image\ImageManagerStatic::make($_FILES['file']['tmp_name'])->resize(300, 200)->save('upload.jpg');//file为上传表单的name名,并将上传的图片压缩成300,200

if ($_FILES['file']) {
  $image = $_FILES['file']['tmp_name'];
  if (is_array($image)) {
    //多图上传
    foreach ($image as $key => $item) {
      \Intervention\Image\ImageManagerStatic::make($item)->save($key.'upload.jpg');
    }
  } else {
    //单图上传
    \Intervention\Image\ImageManagerStatic::make($image)->save('upload.jpg');
  }
}

//水印
ImageManagerStatic::make('upload.jpg')->text('水印文字',20,30,function($font){
  //配置水印字体
  $font->file(\Yii::getAlias('@webroot') . '/simsun.ttc');
  //配置水印大小
  $font->size(30);
  //配置水印颜色
  $font->color('#fff');
  //配置水印水平居左( left, right and center)
  $font->align('left');
  //配置水印垂直居下(top, bottom and middle)
  $font->valign('bottom');
  //配置水印旋转角度
  $font->angle(45);
})->save('uploadWater.jpg');

ImageManagerStatic::make('upload.jpg')->insert('water.jpg','bottom-left',10,10)->save('uploadWater.jpg');