Changing image size while preserving resolution

[dddiam]

In the "Change Image Size" dialog box, one can change either the resolution or the printed image size. Unfortunately, they are linked together. When you change one, the other changes proportionally

What I want to do is to increase the print density resolution (dpi) by keeping the original pixel matrix size (total pixels across x total pixels down), while shrinking the image size.

How do I do that in PE 3?

- David

[Andrei Doubrovski]

David,
In the "Image Size" dialog, uncheck "Resample Image" option

[Wendy]

Hi David ...

When you do that you do have to be aware that Elements will simply make up the extra pixels ... so depending on the image and how much you are increasing it then it may not work too well :)

Wendy

[Karin Sue]

I agree with Andrei. When the resample image box is unchecked the pixels are fixed.

Its a good idea to play with the various options in the resize dialog box till you have a good feel as to how they work.

[dddiam]

David,
In the "Image Size" dialog, uncheck "Resample Image" optionWhen you do that you do have to be aware that Elements will simply make up the extra pixels ... so depending on the image and how much you are increasing it then it may not work too well :)


If I am decreasing the print size, there are no new pixels to make up. So, in that case, would I retain all of the original pixels, unchanged?

Thank you for your help, Andrei and Wendy.

[dddiam]

I agree with Andrei. When the resample image box is unchecked the pixels are fixed.
So then, if I understand you correctly, "filler" pixels are only added at print time, the same as would be done if the original photo had a lower resolution than the printer (at a particular print quality setting).

Therefore, reducing the photo's print size in PE, without resampling, and subsequently enlarging the print size in PE back to its original size, also without resampling, would be lossless. Is that correct?

Also, who adds the "filler" pixels at print time? PE, or the printer driver, or the printer firmware? Or a combination? Which components handle what functions in the printing process?

- David

[Karin Sue]

Pixels will be added or removed if you resize with resampling.

If you resize without resampling no changes are made to the image pixels.

Resolution sets how the pixels will be displayed/printed.

Definitely take the time to open the image size dialog box and try changing the numbers with different options checked and just watch what happens to the other numbers.

When you print and choose to fit your image to a paper size the printer will adjust the resolution so that the print size matches the paper size. I don't know if the printer does any resampling. Minimal I would think. Most printing functions will give you a warning if you try to print at a size that you have insufficient pixels to meet a minnimum resolution for print.

If I am creating something I will generally start with a document set at a resolution of 300 at the largest print dimensions I expect I will ever want to use. It is easy to downsize for web or smaller prints. If I am editing a snapshot I don't worry about the resolution at all. I let the printer make the adjustments when I print and only think about it if I get a message about insufficient resolution--probably because I cropped in too close. Then I rethink my cropping and ponder getting software (like essentials) that specializes in enlarging.

[TonyW]

Also, who adds the "filler" pixels at print time? PE, or the printer driver, or the printer firmware? Or a combination? Which components handle what functions in the printing process?

- David

That gets a little complicated because the printer doesn't print pixels. What it does is converts pixels to dots of coloured inks. Because printing is different from displaying on the screen it also has to convert RGB colors to CYMK.

There would appear to be a general consensus that Epson printers work best when sent images with multiples of 120 (and 360 or 720 would seem to be the optimum).

Canon printers on the other had are multiples of 100 (so 300 or 600 for the optimum).

It would also seem to be the general consensus that it's better to resize in Photoshop/Elements to the optimum rather than let the printer software/firnmware do it.

That said you can find differing opinions and IMHO unless your one of those people who examine prints with a microscope rather than just look at them normally it really doesn't make any difference.

Tony