[BNM] Advice on Comparing base64 encoded images in PHP please.

[John Montgomery]

 > if(md5($imageStr1) != md5($imageStr2))

Is going to compute the md5's for both strings, so if you just want  
to know if the two strings are different it's going to be slower than  
using a strcmp.  Of course if you computed the md5's before hand and  
stored them (and kept them up-to-date) along with the base64 strings  
it would be quicker.

Though, unless you're actually having speed problems you'd be far  
better off just keeping your code simple and sticking with strcmp (or  
surely just a plain old == assuming this is PHP?).

cheers,
	John

On 2 Jul 2007, at 17:46, joseppi c wrote:

> Hi,
>
> I am having to store jpeg Images as base64 encoded strings.
>
> I would like to do a comparison between two images to see if they  
> differ.
>
> Should I just do a:
>
> if(strcmp($imageStr1, $imageStr2))
> {
>  //do stuff
> }
>
> Or speed-wise is it better to compare the MD5 result of each string:
>
> if(md5($imageStr1) != md5($imageStr2))
> {
>  //do stuff
> }
>
> Or does it matter?
>
>
> Thanks,
>
> Joe.
>
>
>
> 		
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