How can I convert low res photos to high res to put on a website

Just in case, complement of information:

after clicking "OK" in the "Adjust Size" dialog,, before closing "Preview", click "File" up there, then "SAVE AS" ( this will produce a new photo, leaving the original untouched ).

In the opening dialog, add a letter ( for instance "A" ) at the end of the name ( since this is a new photo that we want to sit right beside the original, if you choose to reintroduce it into iPhoto, and then into the same Event ) , and change the destination to "Desktop" ( ease of access , and from where you can drag-drop the pic back into iPhoto later ).

"Format" should be "JPEG", and "Quality" set at "Best".

What you are looking for is called "resizing", more precisely here "upsizing" (increasing the pixel dimensions of a pic ) and is easily done this way:

-drag-drop the photo in the "Preview" app that should be in the Dock,

-in "Preview", click "Tools", then "Adjust Size"

-in the first line of this dialog ( "Fit into _______ pixels" ) select " 1024 x 768 "

-be sure "Scale proportionally" AND "Resample Image" are checked

Guess i'll have ( once again ) to demonstrate...Now here's that pic sent to me via internet ( genealogy pic, old scanned photo ) that's 634 by 982 pixels ( making it about 0.6 Megapixels ). It has a "harsh" look to it, and pixelates in even normal view. So i decide to upsample it about 200 % ( 2x wide by 2x high ) bringing it to 1,300 x 2,000 pixels ( now about a 2.6 Megapix photo ). I will now try to ( rrrrolll of drums ) post the results here, and everyone can be the judge as if upsampling a photo is always a bad idea...

Here,s a detail of the original:

And now the same detail of the upsampled photo

The WHOLE photo looks much much smoother !

This upsizing ( or "upsampling" ) technique can be very handy when a web image is so small ( in pixels ) that when you "open it" in iPhoto, it doesn't "fill the screen", like this Studebaker ad ( "Studebaker Commander Starliner hardtop convertible 1953" ) ( Google images ) that is barely 214 pixels wide :

But if you upsize it say ...800 % ( yep, says "eight hundred percent" alright ), you get :

Let's compare with the original ( NOT upsampled ), but zoomed( using Preview app ) to fit the screen :

Now to sum up this thread on a more positive ( and rational ) note : it has been demonstrated that UPSIZING ( more precisely "upsampling" ) is a very efficient tool to deal with any digital image that's too small ( in pixels ) for one's use, or that "pixelates" undesirably.

It has also been demonstrated that the quality of the upsampled image will not degrade, it will in fact improve, which is made abundantly clear here again :

larry,

you write " Trolls are not welcome here " . Totally agree with you on that one ! But i would add " neither are troll rants "...

Crying troll, like crying wolf ( when there is none ) affects the credibility of the "cryer".

You're not embarrassing me , larry...

You're embarrassing yourself.

Not at all - the "new" pixels are created out of nothing by averaging the pixels on both sides of them which give a significant degradation of photos quality - no decent photographer would ever upsize a photo - it is a poor practice and the quality is noticeably worse and depending on how much you do may be incredibly worse - if you go up 5% or 10% you will not lose much (5 or 10% quality) but is you upsize a significant amount you get a very significant amount of degradation

LN

clodo9 wrote:

terence,

you write " Just remember the quality of the image will degrade ".

In fact, when performing an upsizing on a lo-res image, there will be some gain in the visual quality of the photo...

Nonsense, you can't put back what is not there, upsizing will cause the image to degrade.

Larry,

you write " you can reduce photo resolution but you can not increase it ".

This is incorrect: using the same tool, in "Preview" ( or in Photoshop Elements, or other image software ) you can increase as well as decrease the photo "resolution" of a pic ( its DPI ).

Larry, CSound,

here's from Wikipedia ( "image resampling" ) :

"Enlarging an image (upsampling or interpolating) is generally common for making smaller imagery fit a bigger screen in fullscreen mode... there are several methods of increasing the number of pixels that an image contains, which evens out the appearance of the original pixels"

Here ya go: "Enlarging an image for making smaller imagery fit a bigger screen" was exactly what the original question here was all about.

And then " evens out the appearance of the original pixels " is what i call a gain ( albeit small ) in visual quality : the original pic will look jagged, pixellated if zoomed up to the same apparent size of the new one !

P.S.: gee, it would take just a few minutes to TRY OUT what's been suggested above...before posting...as the TOU suggests...

terence,

you write "Just remember that for versions of OS X later than 10.6 that whole post is meaningless"

Sorry, but everything above applies to all versions of iPhoto between ( at least ) 9.2.3 up to 9.6.1, and to all the related OSX versions !

It also applies to all external editors ( Photoshop Elements, ACDSee, etc, including Preview ). It must be noted, though, that the command "SAVE AS" has been replaced in the more recent versions of "Preview" by the command "DUPLICATE", but does the exact same job, and has the same keyboard shortcut :

SHIFT + CMD + S

You are a troll and love to argue even though you usually are totally wrong as you are here and as you were on using DVDs for backup and most all other topics you obsess about

This thread is not about enlarging photos so they pixels - it is about increasing pixel dimensions which is possible by making up new pixels guessing what they should look like and it will always decrease photo quality

Hopefully your mommy will take your computer away again soon and we will not have to subject the volunteers giving actual help and the users who what help to your continued off topic arguing

Please stop posting unless you are posting about a question that you understand and that is involved with the terribly outdated computer and software that you run

LN

clodo9 wrote:

csound

i tried out all this before posting. Why don't you..?

So you tested it but can't be bothered to post the result?

you are not helping the OP and I don't believe you

have a good one

and of course both are terrible quality since it is impossible to upsize a photo without major quality loss as you have clearly demonstrated twice in this old dormant thread

Please stop the Troll posts

LN

larry, you wrote : " if you go up 5% or 10% you will not lose much (5 or 10% quality) but is you upsize a significant amount you get a very significant amount of degradation "...

Ssssoooo.... if we upsize ...say .... 800 %... how do you explain the fact that anyone ( who is not blind ) can see ... we gained in overall image quality ..?

Sorry if i ruffled some feathers.

But truth must prevail...

That is correct - look at the images - they are poor and unusable which is why you can not upsize a photo - you keep proving tha tyou are wrong and then claining tha tyu are right - please give the computer back to mommy and go away

LN