What functions or methods can be used in PHP to read data from image files?

To read data from image files in PHP, you can use functions like `file_get_contents()` to read the contents of the image file into a string, and `getimagesize()` to get information about the image such as its dimensions and MIME type. Additionally, you can use libraries like GD or Imagick to manipulate and extract data from images.

// Read image file into a string
$imageData = file_get_contents('image.jpg');

// Get information about the image
$imageInfo = getimagesize('image.jpg');
echo "Image Type: " . $imageInfo['mime'] . "\n";
echo "Image Width: " . $imageInfo[0] . "\n";
echo "Image Height: " . $imageInfo[1] . "\n";