Image Performance and Bandwidth Question

swissmiss

Hello,

I have a simple question for you guys. I made a script that creates and resizes images dynamically when i feed it a id which outputs the picture using the header function then i call the image like:

<img src="imagescript.php?id=1">

Now my question is... if I am calling a bunch of pictures like that would it be better to just save a copy of the thumbnail ahead of time and call it from a folder or is it perfectly fine to just do this all the time on the fly. I assume saving the thumbnail the first time would be better performace wise but does either option have that much of a difference. I really wanna do whats best performance wise and if any of the two options save more bandwidth that would be great to know as well. Any insight?

I am new to all this so sorry if this is a newbie question. Thank you for your time. 😃

nemonoman

Bandwidth will be the same, but saving thumbnails will reduce the number of cycles used by the server. If you are describing galleries of thumbnails, and you if you know for sure that a large percentage of pictures will have associated thumbnails displayed, then it would be best to create thumbnails ahead of time.

If on the other hand, you don't display many thumbnails, and if you store many pictures that will never or only occasisionally display thumbnails, then your method is OK.

What is NOT a good idea under any circumstances is to store a great big 10000x10000 pixel picture and simply to display it lke this as a thumbnail:

This simply download and displays the great big 10000x10000 picture, although in a small space. The bandwidth used for this is considerable. Creating a low-rez, 50x50 thumbnail is easy, and displaying it:
<img src=ThumbnailOfGiantPic.jpg width=50 height=50>
will be very fast.