Comments on: Get DPI value of an image using PHP

By: Damy

Damy — Tue, 18 Oct 2011 10:47:29 +0000

I was strugeling with this, and since I found it, her you go.

function get_dpi($filename){
$a = fopen($filename,’r');
$string = fread($a,20);
fclose($a);

$data = bin2hex(substr($string,14,4));
$x = substr($data,0,4);
$y = substr($data,0,4);
return array(hexdec($x),hexdec($y));
}

and then print the array or do with it what you want.

Cheers

By: Sartaj

Sartaj — Tue, 19 Jul 2011 06:55:26 +0000

The above code is not working for uploaded image please tell me how to get DPI of uploaded image using php.

By: Sebastian

Sebastian — Wed, 01 Jun 2011 15:43:55 +0000

Sure this would be much easier to do using the imageMagick library. Imagemagick::getImageResolution That should save a lot of hacking.

By: Mohammad

Mohammad — Thu, 04 Mar 2010 16:31:18 +0000

Nice work!
This works well with JPEG images but not for PNG images.

By: Rosario Rojas

Rosario Rojas — Fri, 27 Nov 2009 08:22:24 +0000

This is a very good code. Saved me a lot of work to modify more than 1,000 JPG images.

Thank you very much!!!.

By: Sindre

Sindre — Thu, 29 Oct 2009 22:56:27 +0000

For some reason i get a DPI value: 17490
Isnt this to high? Its just a png-logo..

By: MS

MS — Mon, 19 Oct 2009 14:21:50 +0000

This doesn’t work at all, and I like the author writing:
print_r(get_dpi2(‘filename.jpg’));

when he calls the function “get_dpi” and then call “get_dpi2″ for some reason that I can’t seem to understand.

Lovely function, beside the non-working part.

By: john

john — Wed, 23 Jul 2008 08:40:59 +0000

Man, this is a great function that works really well. However, it seems it can’t read DPI information of a JPEG created on a MAC. I guess encoding methods differ. Do you know where the DPI information is located on a MAC-created JPEG?

By: PHP ile resim dosyas?n?n DPI bilgisini alal?m - Günlük Haftal?k Ayl?k

PHP ile resim dosyas?n?n DPI bilgisini alal?m - Günlük Haftal?k Ayl?k — Thu, 15 May 2008 20:34:17 +0000

[...] Kaynak: Get DPI value of an image using PHP [...]

By: moe

moe — Thu, 10 Apr 2008 09:32:59 +0000

hi,
i know this is way offfff topic, but you think you know how to get a Snap shot of a website in different sizes? if so, could you post it on as a blog or maybe give some ideas and point us to few tutorials that maybe helpful?

thanks a bunch!