Best way of serving images?
 

I have a website which serves images in various sizes (e.g. wikipedia allows you to view the same image in different sizes). The images are uploaded by the users of the site.

Currently, I use PHP to process the uploaded images and store them in various sizes in a database (e.g. small/medium/large).

What is the best way to serve the images? I can think of:

1) retrieve each image from the database each time it is required. (*** This is the way I currently do it ***)

2) store the images as files in a folder in the public web directory and simply link to them.

3) Using the database-retrieval method, keep a store of previously-requested images in $_SESSION and serve them from $_SESSION each time they are required.

Option 2 is probably the most efficient, but I don't like the idea of having a writeable folder in the public web directory. Also, I suspect that doing this would leave the folder open to site-scrapers who could simply retrieve every image stored there.

I would serve the smallest and link the larger (ie view larger) and then fetch it if they click it

You can take advantage of .htaccess to block any 'site-scrapers'.

Option 2 is the best option, with use of .htaccess.

Remember that SEO requires that images that are displayed as X width and Y height should be (in its' original dimensions) X width and Y height. Never use code to resize an image.

Serve your images from the Amazon Cloud and store the common denominator path in the DB. For instance, let's say you have 3 sizes of images. Create three "buckets" in amazon cloud front for each size. Within each bucket, create identical paths to the pictures. Hence, you will have something like: SmallBucket/images/image1.jpg, MediumBucket/images/image1.jpg, BigBucket/images/image1.jpg. All images and paths are the same except for the bucket name.

In your code, you will know when you need a large picture versus a small picture. All you'll need to change is the bucket name within your URL.

You have shared really very helpful information which is helped me so much and I think it will help to many other people who do not know about it.