Displaying Image Stored as Binary in Postgre bytea Column - php

Question

I'm stuck for hours working on this. Few solutions found over the Net but no one seems to help me. I am having problem to display an image on the browser using PHP that takes the image from Postgres DB with column type bytea. I'm sure I'm missing something here. So some guidance are really appreciated. So I have this code below:
$prod = new Product();
$prod->display_latest_product();
if( $prod->exists() ){
$products = $prod->data();
foreach($products as $product){
echo $product->id;
echo $product->binarydata;
/* Solution below: I only get one image with broken link */
header('Content-type: image/png');
echo pg_unescape_bytea($product->binarydata);
/* Solution below: I only get one image with broken link */
header('Content-Type: image/png');
$data=fgets($product->binarydata);
print(pack('H*',$data));
/* bin2hex() expects parameter to be string but resource given */
echo bin2hex($product->binarydata);
/* Solution below: I only get one image with broken link */
$image = stripcslashes($product->binarydata);
header("Content-Type: image/png");
print($image);
}
}
I appreciate some explanation on this because I am still confuse after research and reading.

Answer 1

Finally I found the way to do it. Based on what I found in Handling Binary Data with PDO as I am using PDO to read the column in DB.
So I put these two lines in my foreach loop:
header("Content-Type: ".$product->mimetype);
fpassthru($product->binarydata);
And my file is displayed nicely. As #Musa pointed out that I can only print one image at a time, so I am going to use img with src="thepage.php?img=xx" just to display the image. I am developing e-Commerce app so not sure if this can affect performance because lots of images will be loaded. Any comments or suggestions are welcomed. Anyway I hope this could help people out there who is having same problem.
Documentation on fpassthru is here.
EDIT::SOLUTION FOUND
So I have finally got the real solution that tackles my problem defined in the comment below. And this time it does not involve PHP header at all.
foreach($products as $product){
ob_start(); // Let's start output buffering.
fpassthru($binarydata); //This will normally output the image, but because of ob_start(), it won't.
$contents = ob_get_contents(); //Instead, output above is saved to $contents
ob_end_clean(); //End the output buffer.
$dataUri = "data:image/png;base64," . base64_encode($contents);
echo "<img src='$dataUri' />";
}
I have got the solution here. And based on the comment in that thread, the trick is actually at the buffering. ob_start has to be used in pair with ob_end_clean(). Hope this helps people out there. Thanks.

Answer 2

Assuming that $product->binarydata has contents fetched from the BYTEA column, this method does work:
header('Content-type: image/png');
echo pg_unescape_bytea($product->binarydata);
except when having the client/server version mismatch mentioned in this answer, in which case the escape format for bytea should be used.
The code must not output anything else than the two lines above.