问如何在PHP中调整图像大小后获得正确的文件大小？

EN

// Build the path where I want to save the file;
$filePath="uploads/image.jpeg";
/*
 * Open an input stream relative to $_FILES['file']['tmp_name'] 
 * and write it in an output stream relative to $filePath;
 */
writeFile($filePath);

echo "Before resizing: ".filesize($filePath)." bytes";

/*
 * Create a resized version of the image using imagecopyresampled();
 */
$imageResized = resizeImage($filePath);
/*
 * Actually write the image to the same location of the original;
 */
imagejpeg($imageResized, $filePath);

echo "After resizing: ".filesize($filePath)." bytes";