Pixels to Inches Conversion

coconut wireless · Aug 31, 2006

can SOME ONE help me

when resizing a photo at 200 dpi to a 6"x4" photo what numbers DO would I put in for the pixel size
is it 1200 x 800 ? I am exporting from IPhoto
so what I need is the formula to convert 6"x4" at 200dpi into pixels
when exporting from my IPhoto I have only two options using the original size as shown below or filling in the scale image size.

Example how would I size down the following photo at
full size image @ 1346 x 1301 to a 6"x4" at 200dpi photo

Fill in the blanks below for me
"scale images no larger than width ______ (in pixels) height _______(in pixels)"

I am doing this to meet the requirements of our local newspaper.

thanks for your help

midget patrol · Aug 31, 2006

Pixels / DPI = Inches.

OK. That took me a minute, but I think i understand what you're asking now; you want to downscale the 1346x1301 image to be a 4"x6", 200dpi photo, correct? To do that, you have to sortof work backwards:

First, 4" multiplied by 200 DPI = 800 pixels. So that will be the height of the image.

Next, 6" multiplied by 200 DPI = 1200 pixels. That is the width of the image.

By the way, before i get any farther, 1346x1301 down to 4x6 will not be a clean conversion. There will be some distortion or cropping involved unless the photo is less than four inches high.

Then it's just proportions of the maximum pixels you can have and the pixels you need to get the appropriate height. Sorry I can't walk you through it right now; it's two AM and I'm passing out...

coconut wireless · Aug 31, 2006

well thats what I thought was the formula 6x200 (inches x dpi) and 4 x200
which gave me 1200x800 but Iphoto automatically preserves the ratio by adjusting the pixels you enter. However, it comes out to be larger than 6x4. So I guess what you are telling me is that some photos cannot be converted to a specific size but might be larger as to preserve the ratio? If I put 1200pix in for width the IPhoto automatically puts in 1160pix for height which is definitely going to make the photo larger than 6x4" at 200dpi yes? So with my Iphoto program I can only specify one or the other height or width and than Iphoto will dictate the other measurement to preserve the ratio.
It so complicated
surfin with aloha
the coconut wireless

markc · Aug 31, 2006

1160/200 = 5.8"

Does the paper say it has to be exactly 200DPI, or is that just the minimum? Does it have to be a 4x6 ratio?

At 1346 x 1301, you have a 4.14" x 4" (almost square) image at 325.25 DPI. That's a good printing resolution. Or you could crop it to 1346 x 897, which would give you a print at 224.3 DPI. If it HAS to be at 200 DPI and 4x6, then you need to crop and then resize to 1200x800.

This might help also: The Myth of DPI

LWW · Aug 31, 2006

MARKC is right. 6 X 4 is a 1.5:1 ratio of height X width and your file has a ratio of about 1.03:1.

You either need to hve a different finished size or crop the photo. If you would post the photo you could get opinions on which was the better idea. Some pics are enhanced by cropping while others would be ruined.

LWW

coconut wireless · Aug 31, 2006

LWW said:
MARKC is right. 6 X 4 is a 1.5:1 ratio of height X width and your file has a ratio of about 1.03:1.

You either need to hve a different finished size or crop the photo. If you would post the photo you could get opinions on which was the better idea. Some pics are enhanced by cropping while others would be ruined.

LWW

MARKC is right. 6 X 4 is a 1.5:1 ratio of height X width and your file has a ratio of about 1.03:1.

This is too complicated for me and besides I can only put in one ratio the other is decided by the Iphoto program and is filled in automatically. As I mentioned above the program has two choices: us original dimensions or resize and if resizing I am able to put in one ratio and it plugs in the other number to "preserve aspect ratio" (see sample above) This particular photo it has already been cropped. In order to preserve the photos subjects it cannot be cropped anymore. So because of its dimensions it seems I am not able to get a perfect 6x4? And yes the paper is requesting 200dpi
mahalo for your time

ksmattfish · Aug 31, 2006

coconut wireless said:
So because of its dimensions it seems I am not able to get a perfect 6x4?

Yes, you have a square, and you want a rectangle.

You could force it to fit, but that would mean stretching one dimension by 50%. That would look pretty weird.

You could resize your image to 800x827, and paste it onto an 800x1200 canvas, but then you'd have blank space

I don't know if this will help, but it's where I steer my clients when they are having trouble understanding aspect ratios.

http://mattneedham.com/faq.html#ratio