Php : Convert a blob into an image file

You can use a few different methods depending on what php image library you have installed. Here's a few examples.

Note, the echo <img> is just a trick I use to display multiple images from the same php script when looping through a MySQL result resource. You could just as well output via header() as @NAVEED had shown.

GD:

$image = imagecreatefromstring($blob); 

ob_start(); //You could also just output the $image via header() and bypass this buffer capture.
imagejpeg($image, null, 80);
$data = ob_get_contents();
ob_end_clean();
echo '<img src="data:image/jpg;base64,' .  base64_encode($data)  . '" />';

ImageMagick (iMagick):

$image = new Imagick();
$image->readimageblob($blob);
echo '<img src="data:image/png;base64,' .  base64_encode($image->getimageblob())  . '" />';

GraphicsMagick (gMagick):

$image = new Gmagick();
$image->readimageblob($blob);
echo '<img src="data:image/png;base64,' .  base64_encode($image->getimageblob())  . '" />';

If the BLOB contains the binary data of an image (in a recognizable format like e.g. tiff, png, jpeg, etc), take the content of the BLOB, write it to a file, and voilà... you got an image.

On some strange operation systems you have to give the output file a correspondig extension, so that the image file can be recognised as such.