Walmart 4X6 pics, is it me?

Started Jan 14, 2002 | Discussions thread
Diane B
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Re: Walmart 4X6 pics, is it me?
In reply to Slickone, Feb 21, 2002

Slickone wrote:

Diane B wrote:
When you change (updsample?) from 72 ppi to 180, 220, etc, isn't it
putting in it's own pixels, adding pixels that weren't there to
begin with? Doesn't that degrade the picture also?
I never did anything with the ppi of my pics in the past, just
uploaded them from the camera to the online printer services. I
guess they adjust the ppi for you?

That would be resampling--interpolation--and yes, it does 'add pixels' so to speak. PS's is very good--as well as Qimage--and I'm sure others. You would never be aware of the upsampling within certain constraints (in other words, trying to create a huge image from a small original photo).

However,'resizing' is somewhat different. If you have an image that is 2000 pixels by 1500 pixels (to make it easy) and they are now uploaded from your camera at 72 ppi the dimensions of any photo you would print without resizing would be 27.777 inches by 20.833 inches (2000 pixels divided by 72, etc.). However, the resulting photo would be very pixelated because there aren't evough pixels per inch. If you 'resize' at 200 pixels per inch, then the resulting photo will be 10 inches by 7.5 inches or close to 8 x 10. You must divide the pixels that your camera captured by the pixels per inch for good printing. There are times when you may wish to print a larger print than this--so you would resample 'up'--you may want to print an 11 x 14 at 200 pixels per inch. So--you take 200 x 11 and 14 and the resulting pixels would be 2200 pixels by 2800 pixels. Its unlikely, with a program that interpolates well (PS, Qimage, Genuine Fraactals) that you would ever be aware of this.

Depending upon the size you requested, they may have had to resample 'up' or resize down.

Diane --Diane B http://www.pbase.com/picnic/galleriesB/W lover, but color is seducing me

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