Dumb Ques. re Resizing

[Amy]

I took a Photoshop Elements 4 class earlier this year, and we learned about resampling an image to make it larger or smaller. I've never needed to use this, so I wiped it from my mind.

One of my friends got me a neat little Christmas present - a credit-card size digital photo album. I haven't opened it yet (and it's at home and I'm at work today), but it says that it holds 58 photos; couldn't find anything that said exactly how many mb the memory is. The screen is tiny - like 2 in. x 2 in. or something.

Now I DO remember from that elements class that if you're looking at the photos on a smaller screen you don't need as many pixels as you would if you're going to enlarge it to an 8x10. So my question is......

Would this be a case where I'd want to resample down my photos? I've also noticed when I save a photo as a jpeg in Elements it asks how large I'd like the file to be.....is this what I'd want to do rather than resample? And what's the diff. between resampling and just telling elements to save it as a smaller file?

Thanks!

 

[JustSomeGuyTN]

I don't have elements in front of me right now so I can't tell you exactly. But the size refered to when saving the image is the QUALITY of the image. The lower you choose to make the quality the more lossy the compression will be and thereby the image can be smaller (because there's less detail to the data). The image size in the menu bar (somewhere, maybe under edit) controls the actual number of pixels of the image. It should have an option to change the size by a percentage or an exact number. It should also have an option to lock the height and width to the same proportion or to allow the image to skew. For the keychain frame I would make sure the proportion is locked and change the image height(or width) to fit the pixels of the frame as close as possible. I would guess it's going to be 200 or 100 pixels wide.

 

[seashoreCM]

For a typical digital album or picture frame its not a question of how many pixels you need. Its a matter of how many pixels the album or frame has. The picture album or frame specifies a number of pixels which has no relation to the dimensions in inches. If your picture has a different number of pixels you must resize in order to get the picture to fit in the album exactly.

Whenever you change the size of a digital picture in terms of number of pixels, the process includes a resampling. No choice about that.

If you find you have to change the size a second time, go back to the original and make a change all the way to the second size you want, all in one fell swoop. If you start with the first changed picture and change the size again, antoher resampling takes place. Two resamplings usually result in less quality compared with just one resampling.

Which of course means, do not destroy your original.

Resizing to some percentages looks better than others. Typically resizing to 50% (the original or the resized picture is a multiple of two times the size of the other picture pixel wise horizontally and vertically) looks better than resizing to 45% or 55%. But if your picture frame is not quite right you have to choose between a not quite as good resampling or a picture that does not quite fit the frame.

You may also need to crop the resized picture if the shape (aspect ratio) is not the same as the album. Sometimes the picture looks right on your computer monitor but looks squished in the album. Here you need to stretch the picture a little horizontally or vertically as you are resizing, also preferably all in one move. This may take some trial and error.

The process of making the same sized (in pixels) picture occupy a smaller file is called compression. (You can do both resizing and compression if you wish.) Sometimes you can choose how much compression using such parameters as percent. The less compression the better the picture quality but the picture album may hold more compressed pictures compared with uncompressed pictures. Again it is best to start with the original if you want to reprocess a picture compared with compressing the compressed picture again. Again, keep your original because most compressed pictures cannot be uncompressed back to the quality they had originally (if the process was lossy). GIF is a non-lossy compression method but it doesn't make files as small as JPG which is lossy. Not all picture albums accept all compression methods.

Digital camera hints: http://members.aol.com/ajaynejr/digicam.htm

 

[Amy]

I have a feeling that this is one of those things that sounds incredibly complicated but once I get it figured out, it'll be easy. This will be a good project for me to work on my resizing/resampling/whatever skills. AFTER the holidays when I have more time to think about this.

And yes, I DO know not to mess with my originals!

 

[Groucho]

I would resample your photos ahead of time, just because chances are that the frame's built-in resampling won't be as high-quality as what you can do on your own. Plus it'll be able to flip through them quicker if you go looking for a specific photo, and you'll be able to fit more on an SD card.

Irfanview's batch processing feature works great for this kind of thing - point it to your original photos, have it set to resample to the resolution of your frame, and kick it off. It'll do a high-quality resize of all the photos quickly and easy. You may want to add just a touch of sharpening while you're at it.

You will definitely want to know the exact resolution of your frame though, so you can resample to exactly that. I think most are 1024x768 but I haven't been playing close attention.

 

[Amy]

Thanks! This isn't a digital photo frame - it's just a credit-card sized thing, with a tiny screen. Once I opened it and got to the directions, the screen size is 128x128 (I told you it was tiny), and it does have its own resizing thing built into the software. I played around with it a little last night, and Groucho is right - the built-in resampling doesn't give very high-quality results.

I had some photos that I scanned in at 150 dpi (or whatever option my scanner had), and they actually looked better on this digital photo card than my regular photos (6mp camera, taken on super-fine setting) that I just transferred over to the photo card and let the software resample.

So after the holidays when I (hopefully) have more free time, I'll play around with resampling and see what I can do.

Thanks, and Merry Christmas!