我正在尝试通过 PHP 上传图片，但我无法上传 100% 质量的图片。
我实际使用的代码
class imaging
{
// Variables
private $img_input;
private $img_output;
private $img_src;
private $format;
private $quality = 100;
private $x_input;
private $y_input;
private $x_output;
private $y_output;
private $resize;
// Set image
public function upload($orig, $name, $path)
{
move_uploaded_file($orig, __DIR__ . "/../uploads/" . $path . 'orig_' . $name);
}
public function set_img($img)
{
//$img = __DIR__ . '/../uploads/' . $img;
$img = '../uploads/' . $img;
// Find format
$ext = strtoupper(pathinfo($img, PATHINFO_EXTENSION));
// JPEG image
if(is_file($img) && ($ext == "JPG" OR $ext == "JPEG"))
{
$this->format = $ext;
$this->img_input = ImageCreateFromJPEG($img);
$this->img_src = $img;
}
// PNG image
elseif(is_file($img) && $ext == "PNG")
{
$this->format = $ext;
$this->img_input = ImageCreateFromPNG($img);
$this->img_src = $img;
}
// GIF image
elseif(is_file($img) && $ext == "GIF")
{
$this->format = $ext;
$this->img_input = ImageCreateFromGIF($img);
$this->img_src = $img;
}
// Get dimensions
$this->x_input = imagesx($this->img_input);
$this->y_input = imagesy($this->img_input);
}
// Set maximum image size (pixels)
public function set_size($size = 100)
{
// Wide
if($this->x_input >= $this->y_input && $this->x_input > $size)
{
$this->x_output = $size;
$this->y_output = ($this->x_output / $this->x_input) * $this->y_input;
$this->resize = TRUE;
}
// Tall
elseif($this->y_input > $this->x_input && $this->y_input > $size)
{
$this->y_output = $size;
$this->x_output = ($this->y_output / $this->y_input) * $this->x_input;
$this->resize = TRUE;
}
// Don't resize
else { $this->resize = FALSE; }
}
// Set image quality (JPEG only)
public function set_quality($quality)
{
if(is_int($quality))
{
$this->quality = $quality;
}
}
// Save image
public function save_img($path)
{
// Resize
if($this->resize)
{
$this->img_output = ImageCreateTrueColor($this->x_output, $this->y_output);
ImageCopyResampled($this->img_output, $this->img_input, 0, 0, 0, 0, $this->x_output, $this->y_output, $this->x_input, $this->y_input);
}
// Save JPEG
if($this->format == "JPG" OR $this->format == "JPEG")
{
if($this->resize) { imageJPEG($this->img_output, __DIR__ . "/../uploads/" . $path, $this->quality); }
else { copy($this->img_src, __DIR__ . "/../uploads/" . $path); }
}
// Save PNG
elseif($this->format == "PNG")
{
if($this->resize) { imagePNG($this->img_output, __DIR__ . "/../uploads/" . $path, 9); }
else { copy($this->img_src, __DIR__ . "/../uploads/" . $path); }
}
// Save GIF
elseif($this->format == "GIF")
{
if($this->resize) { imageGIF($this->img_output, __DIR__ . "/../uploads/" . $path); }
else { copy($this->img_src, __DIR__ . "/../uploads/" . $path); }
}
}
// Get width
public function get_width()
{
return $this->x_input;
}
// Get height
public function get_height()
{
return $this->y_input;
}
// Clear image cache
public function clear_cache()
{
@ImageDestroy($this->img_input);
@ImageDestroy($this->img_output);
}
}
并调用上传
$img = new imaging;
$img->upload($src['tmp_name'], $name, $dir);
$img->set_img($dir . 'orig_' . $name); // upload original file
$img->set_quality(100);
// Small thumbnail
$img->set_size(700); // upload thumbnail
$img->save_img($dir . $name);
// Finalize
$img->clear_cache();
结果不是很好，而不是设置quality=100。原始文件（宽度 cca 1100px）已正确上传（服务器上没有调整大小），当我在 Photoshop 中打开它时，将其调整为 700px 宽度并与 PHP 中调整大小的 700px 拇指进行比较，质量差异很大。
查看这两个图像，在 Photoshop 中调整原始大小（顶部）和通过 PHP 调整图像大小（底部） - 文本、图像等模糊，颜色不亮。
Photoshop 中的原始大小200% 放大
有任何想法吗？感谢您的回复:-)