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Posted by: CharlesEF Sep 17 2013, 09:40 PM

Hi All,

I'm looking for advise on how to handle the next phase of my project. I'm working with images (lets say country flags) and I have 1 main image, about 180 x 100. Not all flags are the same size and some flags have a different ratio when compared to other flags (some are wider, some are higher).

1. If I want to display a smaller version of a flag must I generate an image with the size I want OR can I just write the <img> tag with the size I want?
2. How can I know what size the original image is so I can write the <img> tag in a size that maintains the flag ratio? Is there some way to read this information off the server or do I have to maintain a list of each image size?

I will be using .png when I can otherwise I will use .gif format. Or, am I totally off base with my idea? Can anyone suggest a better way?


Thanks for any ideas,

Charles

Posted by: Brian Chandler Sep 17 2013, 10:51 PM

Assuming the images are fairly small to start with, you can just resize them (e.g.) to a standard height using CSS, and let the width adjust automatically. Of course if they are 5MB files, you need to resize them to thumbnails.



You can get the pixel dimensions easily in PHP (forget the details), but as above, in general there is no need to do this.



Either should be fine... In the old days I used PaintShopPro, which made it very easy with gifs to adjust exactly the colour palette being used. Now it seems to be much harder to see what's going on, but I suppose that's called "progress".

Posted by: CharlesEF Sep 18 2013, 10:49 AM

Thanks for the information, I have found the php getimagesize() command which should do what I need. The actual file size is small, average of about 250KB.


Thanks for the help,

Charles

Posted by: Brian Chandler Sep 18 2013, 10:34 PM

But a small flag of Japan (for example) ought to fit in around 200 bytes: see the top of this page...
http://imaginatorium.org/shop/shop.htm

So why do modern systems take 1000 times as much space? Really, quite some progress...

Posted by: CharlesEF Sep 19 2013, 01:23 AM

I might be wrong but I start with a large version of the flag and then reduce it to fit in the space I want. I think I retain as much of the detail as I can this way.

At least that's what I think. Also, I might have overstated the file size since I was not using my laptop at the time and could not check the actual sizes.