small photo to larger size w/out losing softness

[TwoMoon]

Hi. I'm DPI ignorant. I have a small photo (1" X 2"). I want to make it 5" X 7" but every time I do that, I lose the integrity of the photo. It becomes "blocky". I assume this has something to do with the dpi (maybe?). Is there freeware to convert a photo from very small to larger and keep the photo smooth and original? Or can someone give me dpi settings for a 5X7 photo?

TIA

[104456]

you might try a vector mapping package which will give better results such asGenuine Fractals a plug in for photshop .
its not freeware but a Im sure you can find a similar freeware package.

[Jubal]

If you have a scanner with numerous scan resolutions, scan the photo at 2400 and then you can print a 5X7. You can't take a very small photo and just resize it without losing what it looks like. Note that it will take much longer to scan than the lower numbers. You can probably get away with lower than 2400, but I find that works best for me.

[falcon2000]

IrfanView is free and will resample.

Open the image in IrfanView, under "Image" u will find the Resize/Resample option. In there, change the dpi to 250 and width to 5".

But since your file is so low in res. resampling is NOT gonna help you. The resulting print will still look bad.

You'll need a file of 250dpi AT 5"x10" (since the original is 1x2) to get a good print. You'll need to rescan it. Scan it at 250 dpi at 500% scaling.

[jerryctx]

Is the original a:

1) photographic print
2) digital print
3) digital image file on your computer

In case 1, re-scanning at higher resolution may yield a better print. Enlarging will then be limited by the "grain" size of the original film but the "grainy" look of conventional photos is usually less objectionable than the "blocky" look you describe (the human brain is very good at "seeing" the patterns formed by digital pixel blocks).

In case 2, re-scanning will help if the original is high res but your first scan was low res.

In case 3 (and case 2 after re-scan) Falcon2000's suggestion to resize may look prettier, but it wont add detail.

While I'm preaching, let me point out that dots per inch (DPI) refers to the digital printer's resolution. That's not the issue here.
The resolution of the original image captured by a digital camera or scanner is measured in pixels. Each pixel is a number that specifies the color and density of a point in the image. And the image (from most digital cameras) is about one third the size of a postage stamp. It is pixel density that limits the size of digital prints.

DPI refers to the dots of ink a printer lays on a sheet of paper. Note that we rarely print images in the original size so a conversion would be necessary even if there was a one-for-one relationship between pixels and DPI. But there's not. Pixels can specify millions of different color/density values but a printer has only a few different inks (four on conventional printers, six on photo printers, eight or nine on some specility printers). The computer (or sometimes the printer) must perform a huge number of calculations to determine what combination of inks and white space must be used to approximate the appearance specified by the pixel(s) at that point in the image.

Think of the significance of DPI and pixels in this way; Pixels become visible as you enlarge the image. If you need to make big prints, you need a high res camera. DPI are the same (on a given printer) regardless of the print size. High DPI lets a printer do a better job of reproducing the image but its the same at all print sizes.

[falcon2000]

TwoMoon,

As jerryctx pointed out, DPI and PPI are 2 different things. However, in practice the 2 terms very often used as if they are interchangable. This is of course wrong but notheless is the case in reality. Even the famous Scantip.com tutorials use the term DPI to describe digital images instead of the correct term of PPI. IrfanView does the same. Many scanner software use the term DPI in their interface instead of PPI. On the other hand, I've seen printer manufacturers used PPI to describe their printers' resolutions. So don't be surprised to find the option DPI instead of PPI in your scanner software interface.

Jubal,

If you have a scanner with numerous scan resolutions, scan the photo at 2400 and then you can print a 5X7.

This is way way too much. Even at 100% scaling (1x2) you'll still get an image of 480 PPI at 5x10. At too high a PPI you'll actually get a LESSER QUALITY print not to mention that it's just a waste of scanning time, hard drive space and memory used to handle a big (relatively) file like this. Most often you'll need a PPI of only 1/4 to 1/3 of the optimal DPI of the intended printer.

Scantips.com has a excellent explanation of this.

[Jubal]

Thanks falcon2000. I'll check out the tips. But 2400 has worked very well for me.

[Jubal]

TwoMoon, I gave you some bum scoop. The scanning I was doing was slides and if I did not up the scan number I could not get a picture that was readable at any size larger than the slide. I have not scanned any photos yet. However my default setting in my hp software was 200, I assume it was for photos, but would not give me a scan of a slide that was readable. On this subject it would be better to listen to others who have responded even though my scanned slides are very good.

[falcon2000]

Jubal,

It's good to scan slide at your settings. You've been doing good at that setting for slides.