裁剪图像后为什么会出现黑色区域​​？

Question

我的代码裁剪图片：

 function cropimage($x1,$y1,$newwidth, $newheight) {
            $new_image = imagecreatetruecolor($newwidth, $newheight);
            imagecopyresampled($new_image, $this->image, $x1, $y1, 0, 0, $newwidth, $newheight, $this->getWidth(), $this->getHeight());
            $this->image = $new_image;
            $this->image->save($file);
        }

结果：

为什么在裁剪图像后会出现黑色区域​​？如何调整大小？

Answer 1

这段代码修好了：

 imagecopyresampled($new_image, $this->image, 0, 0, $x1, $y1, $this->getWidth(), $this->getHeight(), $newwidth, $newheight);