apophysis-PROBLEMS WITH DPI..

[ranjmahNZ]

OKKKAYYY so ive been creating fractals using apophysis 7x like a madman on a mission! i just got a 12x12 inch canvas printed and it came out saWEEET
only thing is im at a loss as to how i can go bigger bigger BIGGEEERRR... without having to leave my computer on for 2-3 days... haha.....

i just put another 2gb RAM in my laptop (as before i could only render up to 4400x4400 before maxing out my RAM) I now have between 4 and 5GB of available RAM... when i set my render options, in order to get a 300 DPI image of approx 12x12 inches i have to render my flame around 3600x3600 then open the finished fractal in GIMP and specify DPI ... increasing DPI from 75 to 300 (for printing) man this reduces the file by sooo much..

is there any way around it??.. does this mean that if i want to make a quality 24x24 poster at 300 DPI, that i would have to render it at something ridiculous like 7000x7000?........     
SO are there any "apophysis secrets" to choose DPI before rendering? or alternatively is there a way using GIMP or another crazy program to increase the standard 75DPI to 300DPI WITHOUT reducing my actual image size by 4 or whatever it is.....

some of the fractals i have been making are amazing! so much fun to be had creating galaxies inside nutshells.... cheeehooo
thanks to anyone who takes the time to help out
glad to be a new part of the fractal community!... loving all the insane art you people provide for visual simuli.... 

[taurus]

i'm not sure, if i understand, but gimp shouldn't reduce the pixels when increasing the resolution (my gimp 2.6.11 doesn't). Use the image -> scale image dialog and everything should be fine.

a resolution of 7000x7000 isn't ridicolous at all, even if it is hard to make with apophysis.

[ranjmahNZ]

my god are you for real??? although im not trying to increase resolution im trying to increase DPI from 75 to 300 so that i can print in good quality!!
 i have been using the image>print size option...which is right next to scale image HAHA. 

sooooo let me get this straight
 in  image>scale image  when i change the DPI from 75 to 300 it wont automatically bring the resolution down and it wont change the quality of my
fractals???
 this is great because i made a whole lot that i thought i would never be able to print onto canvas or posters...  when i increase DPI in the image>print size
option it was automatically cutting my resolution in quarters haha big lossssss..... time waster too because i printed a whole heap of shirts and some came out slightly under my expectations.... ahhhhhh well learning is sweet..

mmm nectar

to think i had the wrong option in GIMP... simple as that :p  THANK YOUUUU

[ranjmahNZ]

HAH ok so i just had a go at it.... changing the DPI to 300 using scale image option doesnt affect the resolution in the scale image box and it stays the same.
but when i open up image>print size .. indeed the resolution has changed and therefore i can still only get a quality 12x12 inch print of 300DPI
from a 3600x3600 res  fractal (i think this means that increasing the DPI from 75 to 300 in gimp will take my original image and shrink it down so that there are 4 times more Dots Per Inch)   correct me if im wrong pleeease
and once again im back where i started.....

hoooow to increase those dang DPI without losing my original print size??? if im rendering a fractal at 5000x5000 i want it on the wall that freaking big... not a quarter of that size......
end of story mwahaha

[ranjmahNZ]

okay so ive been messing around with the scale image option.... ive figured out that if i scale the image using sinc (lanczos3) that i wont lose
much quality at all while doubling my resolution.... so ive doubled the resolution of a 3000x3000  at the same time as increasing DPI from 75 to 300...
this leaves me with a 6000x6000 that can be printed at 20x20 inches with 300DPI.....    i feel like im doing it right now....
anyone got anything to add??? tips for keeping quality or possibly other ways to deal with this issue?...

much appreciated! chur

[lenord]

I always save all finals in PNG format, I use PhotoShop for setting DPI for Printing purposes. On a 2600x1300 example image, if I set DPI to 300 on it the dimensions automatically change to 10833x5417, now all I have to do is either resize it to the original Dimensions or any dimensions I want and I have a 300dpi image ready for printing, never have a problem.

[cKleinhuis]

ehrm, people, but you know that you loose detail ?
upscaling will never lead to more information
and ridicously upscaling isnt an option, because you will encounter "pixels" in the print ....
so, just go for it an render it at 6000x6000 (just example config )
keep in mind that 300dpi means that you have a fine printing resolution size of 20x20 inches ...every inch gets 300 real pixels, and damnn it, they should be all different from their neighbours

so, in my eyes to not confuse you, why not change the printing resolution down to 72 ?! its not that good, but increasing file size leads basically to the same result, just using far more memory for it ....

[David Makin]

I always save all finals in PNG format, I use PhotoShop for setting DPI for Printing purposes. On a 2600x1300 example image, if I set DPI to 300 on it the dimensions automatically change to 10833x5417, now all I have to do is either resize it to the original Dimensions or any dimensions I want and I have a 300dpi image ready for printing, never have a problem.

Although there you are correct as far as dpi is concerned with respect to fractals you really need to pay attention to ppi (pixels per inch) as much as dpi.
In the case you describe if you leave the pixel size at 10833*5417 then the original pixels are almost 5*5 larger than the original and even smart sizing will not get you the detail to do a true 300ppi image, for that you'd have to render at 10833*5417 in the first place.
In fact even if upsizing (pixels) with Barnsley's fractal based interpolation won't get you back the correct detail.

Essentially if you want a quality print of a fractal at x dpi and y inches wide then you need to render it at at least x*y pixels wide, in fact ideally at a minimum of 2*x*y wide and then resample down (for anti-aliasing) - of course in UF you'd normally do a disk render at x*y wide but with the AA level set as appropriate for the image (from say nothing to maybe 4*4 oversampling).

[lycium]

I've avoided joining the fray here so far, but there's a lot of confusing information flying around and little discussion of the fundamental limits (and their solutions) so I thought I'd drop my 2c...

The biggest disadvantage with rendering large images in Apophysis is the 2GB memory limit (or 3GB if you really push) for 32bit applications in Windows. If you want to render images bigger than this with Apophysis, it goes into what's called "slice rendering" mode, where it essentially re-renders the entire image many times, but only recording the data for a smaller portion of the final image. This is extremely inefficient, and a great way to send your CPU to an early grave

What's really needed is a 64 bit solution for rendering very high resolution images. To this end I've developed a program, Chaotica, which is a modern (multi-core, 64 bit, C++ and SSE optimised) rendering platform for flame fractals. A lot of Apophysis fractals unfortunately depend on 32 bit DLL plugins, and while these are supported in the 32 bit version, they cannot be used with the 64 bit version; even if it were possible, this is a very bad idea since the DLL plugin interface is absolutely terrible (for many reasons, least of which being low performance and virus spreading potential). However, a large number (96) of the popular Apophysis plugins have been re-implemented natively in Chaotica, leading to both higher performance and independence from the 32 bit DLL plugins, allowing fast rendering of very high resolution images in 64 bit mode. There are other benefits to Chaotica besides the 64 bit mode (much higher rendering quality, faster rendering even in 32 bit mode, etc).

Rendering such high resolution images is deemed to be "commercial usage", and as such carries a small cost (US$ 25). If you're interested in purchasing such a licence (there is a second option in case you're interested to follow this next-generation flame fractal development to version 1.0) or would like some sample renderings please contact me.

The free non-commercial version, which can render images up to 1920x1920 resolution, is available here: http://lyc.deviantart.com/art/chaotica-0-4-213481638

[taurus]

so, in my eyes to not confuse you, why not change the printing resolution down to 72 ?! its not that good, but increasing file size leads basically to the same result, just using far more memory for it ....

@ranjmahNZ
listen to the man!

i never thought you only want to pump up your image. my bad...

[ranjmahNZ]

cheeeers everyone! learnt alot from this discussion and ive finally got it all sussed! have now printed some wicked 18x18 inch canvases and they turned out above my expectations.. just getting better and better and cant wait to try it even bigger!!!