Sunday, November 21, 2010

Changing Picture Resolution?

Help!

I'm trying to make a 500 x 500 px picture (at 96 dpi res) to a 500 x 500 px picture at a resolution of at least 300 dpi. When I do this on Photoshop Elements, though, it makes the original picture smaller but the resolution higher.



What am I doing wrong, and how do I make the picture resolution higher without resizing the picture?Changing Picture Resolution?
Yeah, you have to get your basic data source fixed the way you want it from the start, specifically in this case with scanning.



Always scan with the DPI settings set high since you will be given the option to reduce it down anyway.



Its a lot easier reducing an image than to bloat it up with decent quality.



EDIT: Great job emfederin, one thumb up for you. May you continue to be vigilant with helping people.Changing Picture Resolution?
Hey, everybody, thanks for all the help. I think I got it now.



Sorry I couldn't be here to choose an answer myself, but maybe that's a good thing because with the exception of the first, the other two were very thorough.



PS. Adrian, I like your name. :)

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Changing Picture Resolution?
Hey, I like my name, too! =)

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Changing Picture Resolution?
Dots Per Inch is set when you scan the image. I'd rescan the image with a larger DPI setting. of course the larger the DPI the larger the image file is in size.Changing Picture Resolution?
Man, the person above sure do know how to give useless answers.



All things being equal, increasing your dpi when scanning is definitely the way to go, but unless you understand the relationship between dpi and pixels, you may end up just shooting in the dark.

Furthermore, you don't even get a dpi option with things like digital cameras. But I guess some people's %26quot;solution%26quot; to that would be to go buy a bigger camera...



Anyway, graphics can be pretty confusing to a lot of people, so here's some graphics 101 for you:



A %26quot;dot%26quot; on your printer is the same as a %26quot;pixel%26quot; on your monitor.

Increasing your screen resolution is the same thing as increasing the dpi setting on your printer.



There is a small difference, though. A bigger monitor will show you a bigger picture, while a bigger printer just spits out the same sized image as a smaller one.

And this is the simple reason WHY desktop publishing programs define images in pixels, dots, and inches.

These units are used to %26quot;translate%26quot; between what you see on your screen and what you want to print out.



To use your example, your original image is 500x500.

If you print that image at 96 dpi, your physical picture from the printer will measure 500\96, or 5.2%26quot; x 5.2%26quot;



Suppose that's too small. and you wanted a picture that is 10x10%26quot;.

Okay, so multiply 10%26quot; by 96 dpi and you get 960 pixels.



So if you resize your picture to 960x960 pixels and send it to your printer at 96 dpi, you'll have a picture that measures 10x10%26quot; using a ruler.



%26gt;%26gt; OR %26lt;%26lt;



You could take your pixels and divide them by the size you want from your printer, and change the dpi to that:



500\10%26quot;=50 dpi



So if you take your 500x500 image and send it to the printer at 50dpi, you'll still get the same, identical 10x10%26quot; picture.



Now as far as your current attempts, if you send your 500x500 image to the printer at 3000dpi, you're going to get a tiny, tiny little image about 1/6%26quot;.



That's because 500\3000=.167%26quot; (which is about 1/6%26quot;)



So if we define the following as:



PXL = resolution, in pixels, of the image you want to print (the jpg, bmp, etc)

DPI = the %26quot;Dots Per Inch%26quot; that your printer will print the image

PHY = The physical size, in inches, that you want the printed picture to be (as measured by a ruler)



Then you can translate any value to another by:



pxl\dpi = phy

pxl\phy = dpi

dpi*phy = pxl



There are only 2 caveats you want to make sure of:

1) That your printer prints the same DPI down as it does across.



2) That your printer will accept the DPI value you send it. Some laser printers' DPI are fixed (or have only 2 or 3 settings) and will re-translate your image. Some will do this correctly, others...well, not so well. ;-)



Hope this helps.