Some software will encode and send images in hex format. This is not very useful for storing. The solution is to use php pack method to convert the data into a binary string. Then using Imagick you can easily read in the result of the pack and set compression, image format, and dimensions before rendering.

// Pack the hex code
$data = pack('H*', $hex);

// Read the data as blob into imagick
$img = new Imagick();
$img->readimageBlob($data);
$img->setImageCompression(Imagick::COMPRESSION_JPEG);
$img->setImageCompressionQuality(90);
$img->setImageFormat("jpeg");
$img->stripImage();
$blob = $img->getImageBlob();

header("Pragma: public");
header("Cache-Control: maxage=" + 7200);
header('Expires: ' . gmdate('D, d M Y H:i:s \G\M\T', time() + $this->cacheLength));
header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT');
header("Content-Type: image/jpeg");
ob_clean();
flush();
echo $blob;