Rasing DPI

[DiVaio]

I designed a shirt a while ago for some print-store and therefor I need to make my design at least 300 DPI.

Currently my design has 78 DPI, so I need to raise it. Is there an easy way to do this?

[yngve]

I'm sorry, but raising by raising the DPI you will just add pixels, not (color)information, so your image will look as a pixlated painting from hell (much as it would if you used free transform and made it like 200-300% of it's original size). You would have to start out with the DPI raised.

 

I learnt this the hard way, my mother works at a printer, so I have free access to thier printers, so I made some posters in the web-standard (72 dpi), and the result made me almost cry.

Edited July 5, 2005 by yngve

[DiVaio]

So what you're saying is, if a picture has low DPI, you just can't change it unless you start all over again?

Damn that sucks

[yngve]

 

So what you're saying is, if a picture has low DPI, you just can't change it unless you start all over again?

Damn that sucks 

Unfortunally, yes, that's what I'm saying. Since the picture gets bigger (more pixels) but there is no new color information, I'll try to explain it in pic's :

 

The original pixel:

 

The pixels you get when you change the DPI (there is four of them, but they all have the same shade of green, so they look like one big block. thus making the image look pixlated.):

 

The pixels you want:

 

Very crudley done (I'm at work, with only paint at my disposal). Hope you get the picture anyway.

 

 

[ceedj]

Well sort of. yngve is right about the pixel stuff. Higher DPI is ALWAYS better, and yes, most print work requires at least 300 dpi (although I've used as high as 1200 for certain projects.)

 

What you can TRY is get a program like Paint Shop Pro (version 6 or better) or Photoshop, and try either a bicubic resample or a billinear resample when you resize the picture (change the DPI). This is not a catch all solution, and will certainly not ALWAYS work, but I've had SOME luck with it, so it can't hurt to try.

 

But yeah, anything that has to go to a printer (t-shirt screens, photos, whatever), make sure you do your work in at least 300 dpi.

 

Good luck!

[DiVaio]

Thanks for the help guys. Ceedj, I tried to resample the picture but it didn't work. I scanned the original picture again, but this time with higher resolution to increase DPI. The picture's DPI is high enough now to print.

Here is the design btw: