Resizing a photo

[justfly]

I have a photo taken from the Canon G5 that has the following features (on the Photoshop): Pixel Dimensions 5,49M, width 1600 pixels, height 1200 pixels, Document Size: width 22,58cm and height 19,63cm and Resolution 180 pixels/inch.
I have to resize it to less than 100 kilobytes in size and less than 500 pixels wide.
How can I do that on a way to keep a good quality ??
Thanks

[Scottes]

In Photoshop, choose Image... Image Size. For posting choose about 800 pixels wide to get around 90KB, though smaller is better for dial-up users. Ignore the resolution - it's only used when printing.

The choose Image... Mode... Convert to Profile and choose sRGB for the destination profile. Note that it may already be in sRGB which means you can just hit Cancel.

Then choose File... Save For Web. There's a slider with a number next to to it. Move that around until the new file size (bottom right corner I think) go below 100KB. It should still look extremely good for 800 wide, and you can probably go lower. For most images setting that slider to 50 is pretty darn good - I very rarely have to go higher than 60 and 40 is about my lowest limit to keep the quality.

Then just save the image with a new name - don't over-write your original!

[justfly]

Thanks !!
I did that and the final picture got with Pixel Dimensions 446k, width 450 pixels, height 338 pixels, Document Size: width 15,88cm and height 11,92cm, Resolution 72 pixels/inch and size 98Kb.
My only doubt is where should I insert 800 pixels wide as you recommended?? Instead 800 pixels I inserted 450 pixels on the field width on "pixels dimension", as long as the photo has to be less than 500 pixels wide. Is it right?? What 446K Pixel Dimension means?? I mean, how to get this number??
Thanks again.

[Bodryn]

Nice thorough instructions for PhotoShop. Does anybody have similar instructions for Jasc PSP? Either version 8 or 9. Meanwhile, I assume there is something similar in Jasc and I'll try to find it and experiment a little.

[Scottes]

Justfly, don't worry about the pixels/inch or the diensions in cm - they're only used when printing. Be concerned about the pixel width and/or height.

Image... Image Size... You'll see the box below. Once you set the width the height will change automatically (if "Constrain Proportions" is checked).

http://www.itsanadventure.com/postimages/resize.gif

[Scottes]

Bodryn: Image... Resize...
Gets you the following (this is PSP 7 - I'm sure that 8 or 9 is similar if not exact).

http://www.itsanadventure.com/postimages/psp_resize.gif
Choose Pixel Resize at the top, and Maintain Aspect Ratio at the bottom.

Click on File... Save As... switch to JPEG.
Click on the Options Button, then the Run Optimizer button. You get this:

http://www.itsanadventure.com/postimages/psp_optimizer.gif
The image on the left is the original, while the image on the right is what it will look like when it's compressed. I like to scroll to an important feature and view it at 100% - or 1:1 at it says here. This will give you a good idea of what the finished product will look like.

Click on the Format tab and make sure it's on Standard. Ignore the Download Times unless you really care.

Back on the Quality tab... Change the number in the box ("Set compression value") until it gets to a file size you like while retaining the quality. As you can see in this image the final Quality will be 40 which means a file size of 43,557 bytes. The image still looks great and the file is actually quite small and will be a quick download for viewers.

Click OK and give it a new filename - don't over-write the original!

I hope that PSP 8 or 9 is similar to this...

[justfly]

Thanks Scottes !!
I understood it. I did that and the photo got exactly 90K. But if the requirement is a photo with less than 500 pixels wide, should I enter width 500 instead 800 ??
Thanks again !!

[epeace]

as a sidebar . . . resolution for web graphics are typically 72 DPI . . .

[Scottes]

But if the requirement is a photo with less than 500 pixels wide, should I enter width 500 instead 800 ??
Yes.

[newhouse230]

I must be STUPID, STUPID, STUPID....I use an epson 1280, and I print my shots with ppi in the 'image' block of CS set at 72. When I change it to 288 and make a print on Premium Glossy and compare it..with a loupe... to one at 72, I more often as not choose the one printed at 72 as more detailed...or at best it's a dead heat. I have repeated this 'endlessly' and using shots of tree branches and other highly detailed matter, I simply cannot see a positive difference.
I assume I must not be 'getting' something, since just about everyone on the web says to to resize and change ppi before printing.
Any thoughts on what I am 'missing?'

[Scottes]

The print driver may be ignoring the DPI setting. For instance, if you specify that the image should fit full-width on a 4x6 then the print driver doesn't care about the DPI - it will resize or shrink to make sure that image fits a 4x6 full-width.