Going BIG with not s many pixels...

[alessandro.vasapolli]

Hi,

once in a gallery (I mean in the "real" world) I saw some very big (1 meters x 1.5 at least) so sharp that you

could say you were inside of the actual scene in the picture...

They were BEAUTIFUL...

 

Now, I really think they were made with a big format camera but since I don't have one I talked to the guys at

the lab and they told me that "out there" there are some kind of interpolation software that are much better than

PS in doing this operation (I mean incrasing the resolution of an image) and with a native 20 megapixel image you

could go up to 40 and make a decent big stamp.

They knew there are this type of programm but they don't know the name... :-?

 

Can you suggest me some name for this programm?!

What do you think!? Are they realy good as they told me or not!?

 

Thanks a lot in advance for your contributions!

 

 

Bye

 

 

Alessandro

[bruce_watson1]

No software can create information where none exists. If all you have is 20 Mp, then that's all you have.

 

That said, there is software like Genuine Fractals which can interpolate your pixel size upward. But programs like this just generate more data, they do not, and can not, generate more information.

 

For example, that branch way in the distance. When you use a software product to uprez your image, it's job it to make sure that branch doesn't get the jaggies. But it can't show you the texture of the bark on that branch, because your original capture doesn't have that information.

[Ed_Ingold]

There aren't many 20MP cameras out there, other than the Canon 1dsMkII or medium format backs, so we are talking about really expensive gear. Even so, it takes good lenses, a good tripod and good technique to get sharp pictures of this size.

 

Digital images can be resampled by a factor of two or more without leaving artifacts, which would easily produce prints the size you describe. The purpose of resampling is to render the pixels too small to be seen on the print. While resampling does not add information, it doesn't take any away either.

[manuel barrera houston,]

some time ago, I read an article that tested the different ways to interpolate an image, the conclusion was that there is so little difference and that CS3 was good as any of the others. Don't recall where I read it.

[steve_swinehart]

"some time ago, I read an article that tested the different ways to interpolate an image, the conclusion was that there is so little difference and that CS3 was good as any of the others. Don't recall where I read it."

 

Then whomever wrote that is either not very sophisticated in what they're doing, not very discerning, not making large images, or they don't know what they're doing.

 

There are at least 3 programs that will upsize an image far better than PS. The real problem with upsizing is in interpolation of vectors - that is, curves and diagonals. Every program will do horizontal or vertical straight lines - that's easy.

 

PS will make 4-6 pixel edges on curves or diagonals where it tries to not make stepped edges. Genuine Fractals will turn small details into solid objects. Sending the image directly an inkjet printer and letting the printer driver interpolate will leave stepped (jagged) edges. Kneson Imagener will do a fairly good job. PhotoZoom Pro 2 is okay but not as good as Kneson.

 

If you're sending the images out - let the service bureau upsize them for you. If they're making inkjet prints they should be using a RIP and that will provide superior interpolation. Or, if you're printing with a LightJet or Durst machine - it will have interpolation sofware built-in.

 

The answer is yes - if you're using a 20mp camera - 30x40 prints that are good looking are not out of the question.

 

I make 18x28 inch prints from a 10mp camera, and they look good enough to be displayed next to 6x7 film prints of the same vertical dimension.

[kari v]

20Mp --> 40Mp, let's say about 5200x3900 --> 7300x5475. In pixels that's only 2100x1575 increase, or 3,3Mp. Interesting, isn't it. "2x" interpolation with a clean file isn't a problem.

[manuel barrera houston,]

Now Steve that is very powerful language and a lot of technical stuff, now explain how the very large image with three other programs are better in plain English, I have genuine fractals and do not notice much difference. Now while I admit that I do not recall the source, the source was from memory was well known. What makes you an expert. What are the other three programs, and which one do you use. I stand by what I said until you can bring some proof to the table. If you can manage to do that, I will spend time going back to locate the article. One of my camera club members uses a 20d and a 500 L lens and often brings 20 x 30 images using ps, very sharp images.

[martijn_houtman]

<p>

Hmm, from a scientifical approach, these "uprezzers" are interesting, but most examples I have seen introduce weird-

looking artifacts. In most cases, I would actually prefer a bit blurriness rather than the smart-interpolated versions.

</p>

<p>

I think what you are referring to is the differences between regular cubic interpolation and sharp cubic interpolation and

such. Software like Genuine Fractals produce very different results.

</p>

<p>

Kari, your calculations are incorrect. 20MP to 40MP is exactly what it says: a 20MP increase. In image <i>size</i>,

however, it matters less, as the image will only increase about 1.4 times in size in both directions.

</p>

[manuel barrera houston,]

By the way Steve, I use the stair method in photoshop, I have created an action where the increase is only by 5%. Fred Miranda uses 10% which is normally the recommended way of doing size increases.

[alessandro.vasapolli]

Ok,

but, at the end, which software should I use?

 

How can you get very good results, compared to the medium format, with 10mp?

Do you use any kind of tecnique to increase the size of the picture in particular?

What is the story about the increments of only 5%?! Should I keep increasing the size going up 5% each time?

 

Thanks a lot!

 

Alessandro

[manuel barrera houston,]

The sharpness will be as good. However, the bigger the image the further we stand away from it. so that sharpness becomes an issue for pixel peepers. So the answer is it will not be as good. If that is the type of sharpness you want have to go at least 16 mega pixels or higher, 1DsII or III, Canon 5DII (probably), For landscapes that is the way to go and you have the lens that will be able to capture the sharpness.

[john_reynolds10]

<p>"some time ago, I read an article that tested the different ways to interpolate an image, the conclusion was that there is so little difference and that CS3 was good as any of the others. Don't recall where I read it"<br>

It may of been Patrick Lavoie's post here (somewhere!) where he did some experiments and concluded that Photoshop was superior to other methods.</p>