Viewing post #1580501 by Australis

TsFlowers said:On break away from the computer I got to thinking. Even if you squish a 1200 x 2400 pixel photo into a 600 x 1200 pixel space, you still use the same amount of data transfer, the space of the original photo. I understand that they are resized, but do you understand how that re-sizing is done? I mean how is it done? The photo itself isn't changed to a new size is it?

I myself used PageTutor to learn to write simple html. My understanding is that you can put a 1200 x 2400 pixel photo in a 600 x 1200 pixel space, but you use the same data transfer. Therefore PageTutor suggests cropping the photo to post, but keeping the original. Larger photos cause slower loading.

There are two possibilities here - (1) scaling or (2) resampling. If you just scale a photo (like what I think you're saying PageTutor does), it doesn't change the image itself - it uses the browser to limit the size to which it is displayed. If you resample an image when resizing it, however, then the image is actually changed. As far as I am aware, this is the process that @dave uses, as by reducing the number of pixels in the image you also generally reduce the storage space required for it. So the only time you're transferring the full image is during the initial upload from your computer to the NGA website; Dave's scripts then resample it (if required) and store the resampled file.

TsFlowers said:... it just seems some (many) when I click to enlarge they are so large that I can't see them properly. They take more than the entire screen which they are in and I have to scroll. Just my opinion, I don't like to have to scroll sideways or up-and-down to see a large clear photo.

What you can do it is alter the zoom in your browser temporarily if the image doesn't fit on your screen. Most browsers have a View > Zoom option in their menu. There's also these keyboard shortcuts:

CTRL - (that's control and the minus key) to zoomout
CTRL + (control and the plus key) to zoom in
CTRL 0 (control and zero) to reset the zoom to default