Resizing Images without changing the proportions or losing quality

Question

Hi my client has given me a load of images for the site I'm building for him, they are going in a Javascript Image Nivo Slider Banner at the top, the size of the banner is 720px x 200px but the images aren't.

I can crop the images, but I wonder if there is a way to resize them and change the proportion without destroying the quality, or due to the nature of how pixels work is this not possible?

I would like to be able to turn them into wide angle images and work from there.

I have Photoshop CS6 Ext.

Answer 1

It is not possible to change the size of already existing images to 720px x 200px without losing on quality or content. Best you can do is that crop the image in this ratio so that maximum information can stay on the banner.

Answer 2

As Scott pointed out: the only way to change proportions is to crop, but you can size the item as close to one of the desired final pixel dimensions first, and then crop.

For a naive (mechanical) way, you merely set the smallest dimension of the original image to the correct size for that dimension. The other dimension will be larger than the desired final size on that axis, so you can crop to the image. Many (most?) photos have the focus in the center, so you set up the crop so that the edges are cut (crop to the center).

As far as resizing without quality loss, all resizing is a loss in quality. Sizing down throws away data, and if you are not resizing by a factor of two in both directions, there must be some math involved that decides how to deal with it. Downsizing is usually OK even by larger percentages, but the image will become blurry.

Upscaling by more than 50% or so should be avoided, since you will be enlarging the flaws in the original image as well as adding new flaws.

Exactly how much you can get away with in either direction is going to be a personal decision, but I will say that when I get images too small for the desired placement, I groan, something I do not do when I have to downsize.

Any automated process where the multiplier is in the range of "original image dimension times (.5 to 1.5)" is probably going to be fine without user intervention.

Answer 3

there is one plugin called http://www.alienskin.com/blowup by using that plugin we can resize image (smaller to bigger, bigger to smallar& stretchable) with out losing quality but i am not sure of 100% quality...but its better it may help for u....

Answer 4

Depending on the picture you could mask out the objects or logo in the foreground and only resize the background, or resize front objects independently and proportionally. Kind of like the content-aware-scaling in Photoshop. If scaling is the only option I suppose Scott boiled it down pretty much.

Answer 5

You can make pictures smaller by saving the aspect ratio. so you never lose any quality.

For example we have a 400px x 200px image it's aspect ratio is 2w X 1h. So if you want to make the width 280px then the height must be 140px (width/2) to save quality.

All other resize attempts will result in a noticeable quality loss.

In your case: make the images smaller as much as you can with saving aspect ratio then crop.

Answer 6

In my case I was trying to resize a large image to a small size where 12% of reduction happened... and each and every time the image was pixelated in some way in photoshop. My solution was to take the large png image open it in ilustrator then click in "live trace options" select "high fidelity photo" option then "expand". The result was amazing. Then resize it as I want. Save it and put it in my design or open it in photoshop.

Answer 7

Just put your large, edited image in PowerPoint, resize it there, and print. I just took one that was sized in CS6 as 38 inches wide and made a perfect 4x6 out of it with no lossy issues. As we used to say in the old days when we had to do our own programming, the best solution is the simplest one, or what we used to call an "elegant solution."