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Stormyguy
Jul 21, 2005, 01:36 PM
Just a quick question...

I'm guessing this probably isn't possible, simply because there's not enough info in the original pic but is there any way to enlarge a small image that's only 3/4/5 cm across to perhaps double the size or "double and a bit" without it going all "pixely".

I have an image that's small, poor quality that I'd like to enlarge to print on a T-shirt.

Excuse my ignorance but I know that I've always found answers to solve-able problems here before! If this one's not poss to solve then so be it!

I have Photoshop (Elements OSX) and full Photoshop for Classic.

Thanks in advance



iLikeMyiMac
Jul 21, 2005, 01:40 PM
Just a quick question...

I'm guessing this probably isn't possible, simply because there's not enough info in the original pic but is there any way to enlarge a small image that's only 3/4/5 cm across to perhaps double the size or "double and a bit" without it going all "pixely".
It's probably not but in the prefs in photoshop could could try changing the way it resizes images. I think to bi-cubic filtering.

scem0
Jul 21, 2005, 03:34 PM
Depending on the kind of picture it is, you could convert it to a vector graphic, and then enlarge it. I'm pretty sure photoshop can do this, but I've only done it in flash and illustrator. It wouldn't work so much for a photograph, but for clip artish type things, it would work quite well.

scem0

Stormyguy
Jul 21, 2005, 03:51 PM
Depending on the kind of picture it is, you could convert it to a vector graphic, and then enlarge it. I'm pretty sure photoshop can do this, but I've only done it in flash and illustrator. It wouldn't work so much for a photograph, but for clip artish type things, it would work quite well.

scem0

ok thanks for the replies - my image was originally just a gif but i 'grabbed' it as a tiff so there seems to be more substance to the image than as the gif. i DO have illustrator too but any pointers on how to 'vectorize' wld be appreciated,....



edit: OK, I opened up my image in Illustrator and 'fiddled' about with it and have managed to enlarge it without TOO much distortion - but I have no real idea how I did it! I'm not very familiar with Illustrator!
I'd still like to learn if/how I can make it bigger and retain a crisp image if anyone has any info??

MontyZ
Aug 2, 2005, 04:28 PM
The simple answer is No, you can't enlarge a small photo and retain the original sharpness. It's going to look a bit fuzzy or blurry no matter what you do. Sharpening filters won't be that effective, either.

Now, this blurriness might not be a problem if you're transferring the graphic to a t-shirt, and you might be able to incorporate the blurriness or pixelation into the actual design.

For the most even results, I'd recommend enlarging the image in 50% increments if possible: 100%, 150%, 200% etc.

53buick
Aug 2, 2005, 04:48 PM
The simple answer is No, you can't enlarge a small photo and retain the original sharpness. It's going to look a bit fuzzy or blurry no matter what you do. Sharpening filters won't be that effective, either.

Now, this blurriness might not be a problem if you're transferring the graphic to a t-shirt, and you might be able to incorporate the blurriness or pixelation into the actual design.

For the most even results, I'd recommend enlarging the image in 50% increments if possible: 100%, 150%, 200% etc.

yeah, what he said.

you could try the auto trace tool in Illustrator and try to enlarge it as scem0 suggested.
or visit this site if you want to make a mural (made up of tiles):

rasterbator (http://homokaasu.org/rasterbator/)

neildmitchell
Aug 2, 2005, 08:25 PM
Have you tried Illustrator CS2 live trace.
Live Trace in the new Illustrator is unbelievable.

Depending on the quality of the image, you can get near photo quality vector artwork using Live Trace. Then from there scale away

CanadaRAM
Aug 2, 2005, 09:21 PM
It makes a big difference if your original image is "graphicy" or "Photorealistic"
A GIF or a TIFF is a raster graphic, that is, it is made up of discrete pixels, and if you enlarge it, the pixels get larger too (we'll cover interpolation in a moment.)

If it is a graphic with sharp edges and blocks of solid colour and type, then you may be better going the Illustrator / Freehand route and redrawing it as a vector graphic. Note that we are not talking about enlarging the original image, but starting with the original as a template only and re-creating it by redrawing the shapes and re-setting the type.

It is a pain to do if there is a lot of detail or colour graduations - auto Trace tools can help. But once it is a vector drawing, you can re-size and re-colour to your heart's content, without losing any resolution; this is because it is no longer composed of pixels, but of lines and shapes defined by equations - like a cartoon thather than a photo. (The latest issue of Layers magazine has an article about how to make a vector drawing from a photo).

OK, what if it's more photorealistic though, with lots of colour blends and soft fuzzy edges? You can increase the size or resolution of a raster graphic in Photoshop and other "paint" or "photo", the original pixels will be spread apart, with spaces in between them, and the program will try and fill in the spaces with its best guess at what colour the intervening pixels should be. This is called "interpolation", and there are various formulae to calculate the best guess. Generally, these do a good job of smooth areas of colour, and less well on sharp edges and patterns - which get blurry. It also tends to accentuate any noise, 'dirt' or grain in the original.

If you are trying interpolation, try doing it in small steps of 130 - 150% at a time, rather than giant leaps. Also - enlarge it by steps to about 2 x your desired final size. Do not add sharpening at this time. Use the Dust and Scratches, Despeckle or Blur filters to smooth out the grain and noise in the enlarged image. It will look a bit fuzzy but more pleasant. Now scale it down to your desired size. This will gain back some apparent sharpness and detail. Now, at the very last, add a judicious amount of Unsharp Mask or Sharpening. Try to avoid visible halos around objects. (remember too you can use the Lasoo tool and Selection: feater to choose specific areas to blur or sharpen).

If there is type in the graphic, you might still consider re-setting it. Your readers will pick out flaws in type very quickly. In Photoshop, use a Layer to paint in a patch over the existing type and then a Type Layer for your new words, matching font, size and spacing as close as you can. You can pick up the original text colour with the eyedropper tool. Edit non-destructively -- Keep all your layers so you can come back and edit again. You may have to rasterize (a copy of) the type layer and blur, colour adjust or distort it some until it matches the underlying image.

If you can spend a bit, get the Genuine Fractals plugin from -- Lizardsoft? -- it does a much better job of creating an interpolated image even at extreme magnifications.


Thanks
Trevor
CanadaRAM.com

Stormyguy
Aug 3, 2005, 02:00 AM
Wow,

Thankyou one and all! I will be having another go at this over this weekend (as I need to sit down and apply myself to this little project properly) and I'll be sure to take on board all this info and try the techniques offered here!

The graphic is a TIFF so will be heading down that route.

:)