Changing picture resolution - possible?

[ddmarsh]

I was using my new digital camera and didn't realize the resolution was set on the highest setting. Is it possible to change their size after the fact (they have been uploaded to my computer) and if so, how (with details please!).

Thanks in advance -

[papal]

Debbi,
As far as i understand it, resolution and image size are two different things. The resolution (number of pixels per square inch?) defines how clear you want the image to be (basically if you want to enlarge it, it will start getting fuzzy faster at a lower resoution). The larger the resolution, the larger the size (in memory, not physical size) of the image file. You can change the resolution by going to the menu in your camera usually.

Now the physical size of the image is something else. I don't think you can change the image size setting in the camera. But after you have downloaded it to your computer you can use any imaging software to resize it. (i use photoshop). The software that came with your camera may even do that for you. Just look for a menu that says something like Image and a sub-menu that says Resize.

I am not entirely sure if what i am saying is right (i don't have a digital cam)... so someone please correct me if i am wrong!

[LD92599]

What you need to do (one thought!) is download a program that will allow you to change the image size (not the resolution!) of an entire folder of pictures at once.

We use this (we have a mac) http://mac.tucows.com/preview/206512.html and it works GREAT! We have an 8mp camera, so we tend to use this program alot for when I want to update our website or email a bunch of pictures out.

You can do a search on a site such as Tucows (http://www.tucows.com) for image + resize and see what comes up.

It's quicker to use a program such as this than to manual resize each photo, which is way too time consuming, IMHO!

Laura
mom to William
3.5.2003

[egoldber]

My camera has an option where you can set the resolution, but I always leave it at the highest setting. If I want to re-size a photo, I do it one at a time, since I generally re-size very few photos. I don't re-size them if I just want to put them on Shutterfly or something. I never e-mail photos, so that's not something I worry about.

Generally, I think its best to leave them at the highest resolution. That gives you the most flexibility on what you can do with your photos.

HTH,

[MinnieMouse]

You need an image manipulation program. Photoshop is the graphics industry standard but is VERY pricey. But they have a "lighter" version of the program that is much cheaper (~$99 I think).

Here is the thing...TRUE resolution is giving in pixels in two dimensions... ie 1024x768 that means that my monitor is set to show me 1024 pixels horizontally and 768 pixels vertically on my screen. Most digital picture images are assigned resolution in that format and have a dpi of 72.

DPI (dots per inch ...AKA PPI pixels per inch) is a single number like 72dpi. That means for every inch of my image there are 72 pixels both in height and width.

So if we take both of our examples.... If my picture has a resolution of 1024x768 and it is at 72dpi, then it should be (divide 1024 and 768 both by 72) 14.2" x 10.6".

72dpi is perfect for sharing on a monitor. Anywhere on the internet or emailing to someone that is JUST going to view it on screen. But printing isn't a good idea as it would be very blurry. Anything printed should be at 300dpi. BUT if you took a file and just changed the dpi up from 72 to 300, all your computer would do is split every pixel in three so even though it would SAY it was 300dpi, the picture would be just as fuzzy as the 72dpi one.

Computers, although they allow you to, don't "make" pixels well. You can always take pixels away but making them makes for fuzzy prints. Here is a slide from a presentation I do here at work that helps explain how you can change dpi and image size to get good prints.


http://www.windsorpeak.com/dc/user_files/2758.jpg

Notice where it shows 1200x800 pixels. That pixel dimension or resolution is important to either maintain or decrease, it can never increase. So if you have a file with that resolution, then you can safely bring the physical size of the image down if you are sharing it on the web and you won't have to adjust the dpi. BUT if you are printing it you need to be aware of the physical size and the resolution. If the file is 1200x800 and you want to print it, since 300 divides into 1200 four times you can safely divide the physical size of your image by four while increasing the dpi to 300.

I know this is all confusing which is why I included the above jpg. The slide is more geared to scanning something at a high enough dpi, but the proportion issues are still the same if you are reducing resolution.

I'm sorry this is clear as mud.... read through this and ask more questions...it's difficult to explain this without back and forth interaction.

HTH

Christine

[MinnieMouse]

I forgot to add....

It is ALWAYS better to save ALL your files at the highest resolution that you will ever use it at. In other words save your digital camera files at the highest resolution. That way you can make prints fairly large and not worry about fuzziness.

If you want to share them online, then resize/reduce the resolution and save a SEPARATE file for that purpose retaining the original high res image.

You can ALWAYS throw away pixels but you cannot make new ones. That is why it's important to save the original high res image.

HTH

Christine

[ddmarsh]

Wow you guys are so knowledgeable! So I should use the highest resolution and then change it, I didn't think of that. I do have the less expensive version of Photoshop, just haven't installed it yet, will that do it also?

ETA: Yes Christine that whole thing while brilliant I'm sure from your presentation went way over my teeny tiny technical brain - it will take me some time to figure out, LOL!


thanks

[newbelly2002]

Yes, I second that. Having found out the hard way.

We bought a new digital camera (4 megapixel) days before DS was born. Needless to say in those first few weeks we were still learning. I took an amazing picture of DS sleeping on my Dad's chest--both of them out cold. Unfortunately, the camera was set to the lowest resolution. The picture looks fine on screen, but can not be printed out at anything larger than a 3 x 5 without a significant sacrifice of quality. It still burns me everything I see it as the picture is on of my all-time favorites.

The camera is now, permanently, set to high resolution.

Paula
Mama to Dante, 8/02

[flagger]

>Wow you guys are so knowledgeable! So I should use the
>highest resolution and then change it, I didn't think of that.

It depends on if you plan on just emailing photos or putting them up on a website. For that, 72 DPI is more than adequate. If you plan on printing anything, then always shoot at the highest resolution possible. It makes a huge difference especially if you want enlargements.

> I do have the less expensive version of Photoshop, just
>haven't installed it yet, will that do it also?

Yes it should.

Here are a couple of forums I hang out that can provide loads of help just by reading some of the posts.

http://www.broadbandreports.com/forum/dimaging

You will find a bunch of Photoshop and Photoshop LE tutorials in this thread as well.

http://www.broadbandreports.com/forum/remark,2156462~root=avatar~mode=flat

HTH

[MinnieMouse]

Let me see if I can explain in a different way.

A pixel is a kind of measurement but unlike inches or centimeters it can change size. If I had a 3"x3" picture that was 3dpi then each pixel would be an inch, if I had a 2"x2" picture at 100 dpi then each pixel would be 1/100th of an inch. Follow??

So if I have an image (I'm going to use nice round numbers makes it easier to follow :-) )that is 1200 x 900 and is 100dpi than each inch has 100 pixels in it.

Here is a new slide that shows a sample of a camera file and a print file and how the resolution and dpi change with the size.


http://www.windsorpeak.com/dc/user_files/2763.jpg


Is that any clearer??

Edited to add... The example was for the original camera file and a PRINT file. If you want to share something online you can make the resolution LOWER than the original (ie in the example above you could make an image 4x5 and 72dpi) w/o compromising the quality of the displayed image. If you do the math, 4x72=288 and 5x72=360 which would make the resolution 360x288, well below the 1200x900 we started with. As long as you don't go above the original resolution you will always have a quality image.

Basically it all boils down to ....

**For file saving the higher the resolution, the better.

**Print or display pictures online at the correct dpi. A higher dpi will just take longer to send, load, print or display and NOT give you a better picture. A lower dpi will be fuzzy, the lower the dpi, the fuzzier the picture.

HTH?

Christine