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Tuur

Sage

  • "Tuur" started this thread

Posts: 3,387

Location: Netherlands

Occupation: Krpano custom coding / Virtual Tours / Photography / Musician / Recording engineer

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1

Friday, October 30th 2009, 10:27pm

OT:jpeg quality etc

Hi,

i like to know something more about picture size and jpg quality...

oke... the picture is stitched and saved full size.. 10000x5000 psb 300 dpi..

open in photoshop... edit and so ... save as jpg (no tif in krpano on a mac...yet) what jpeg quality should you recommend???

should i change the size to 5000x2500 and do jpeg quality 12 or stay 10000x5000 and do quality 7 or 8...

now i did 10000x5000 quality 11 so it's 20mb that's big... but works nice...

Are there rules?? and logic? i like to know when it gets interesting to use the multi res droplet... i use it always but i can imagine that when you do 10000x5000 quality 8 (aprox 3.5MB) u don't need that...


sorry ... but i'm really confused... *cry* *blink* *confused* *wacko*
ofcourse i want the pictures sharp, nice color, good defenition when zooming and running smooth and loading fast...

I like t o hear from you all what you do, why...etc and want to understand really..

Thanx

Tuur *thumbsup*

juliorosq

Beginner

Posts: 7

Location: tenerife, spain

Occupation: turism

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2

Sunday, November 1st 2009, 12:49pm

Hi Tuur,

one think that i do, is not to save it at 300dpi, as far as I know this you should do it for printing, i hear that more that 150 dpi for Internet is too much, I'll pass you a link when i get home of a tutorial about everything about definition, sharp, and quality.

regards

image360

Intermediate

Posts: 207

Location: Austin, TX and Chicago, IL

Occupation: Photographer

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3

Wednesday, November 4th 2009, 1:49am

Image Quality

Tuur,

There are books about image quality, it's not a simple subject at all to truly optimize. But in general a few tips are:

1. don't worry about ppi or dpi for the internet - it means nothing! ppi and dpi are just a text marker in the file, nothing more. It's a bad legacy design from the print industry. The ONLY thing that matters here is the pixel dimensions, you can call it whatever ppi you want to, does not change hows it's viewed here.

2. For EQ and full screen, many like about 6,000 by 3,000 pixels, For cubes about 1,600 pixels seems to be a reasonable trade off. But then of course there is multires from KRPano. This changes everything, but not without a lot more complexity if you want to optimize it to the extend possible - with more options seemingly coming every day. *thumbsup* Klaus!

Multires now has many options, at least here, and is best explored on how you want to use it. Do you have a standard display or stage size you target, how much do you allow the viewer to zoom in, what are your assumptions on the viewers computer, etc. al.? And of course how long will that last given the ever increasing move toward 16:9 aspect ratio as a new standard?

And once you figure that out, it might not be the same for every pano or image. Some scene's compress really well at 5 while others may require 10. And watch the JPG scale, it's not as standard as you would hope across applications.

Lots of choices!

Regards,

Robert

4

Saturday, March 6th 2010, 8:57pm

RE: OT:jpeg quality etc

Hi everyone;
I´m just new whith KRPano, and of course I have some questions. I have a 1000X5000 image and Ido the multires process, the swf file is 17 mb, isnt that file too big for load in the web? In your experience how long it will take to load?? Rigth now I´m using the demo so i can not see the pano in the trough the web. Can somebody help me with this. Thanks !!
Hi,

i like to know something more about picture size and jpg quality...

oke... the picture is stitched and saved full size.. 10000x5000 psb 300 dpi..

open in photoshop... edit and so ... save as jpg (no tif in krpano on a mac...yet) what jpeg quality should you recommend???

should i change the size to 5000x2500 and do jpeg quality 12 or stay 10000x5000 and do quality 7 or 8...

now i did 10000x5000 quality 11 so it's 20mb that's big... but works nice...

Are there rules?? and logic? i like to know when it gets interesting to use the multi res droplet... i use it always but i can imagine that when you do 10000x5000 quality 8 (aprox 3.5MB) u don't need that...


sorry ... but i'm really confused... *cry* *blink* *confused* *wacko*
ofcourse i want the pictures sharp, nice color, good defenition when zooming and running smooth and loading fast...

I like t o hear from you all what you do, why...etc and want to understand really..

Thanx

Tuur *thumbsup*

5

Saturday, March 6th 2010, 9:04pm

I tried some tests comparing different sizes V lower quality when using pano2vr
thomas told me the quality was the issue rather than the size ( if I understood correctly)
but I thought a smaller image at higher quality was better looking than a bigger image at a lower quality for the same file size
DPI is irrelevant.
maybe there is an optimum ratio to reduce an image ?
[edit] the nice images you see I think the maker understands contrast, sharpening, saturation etc better than I do

Zephyr

Professional

Posts: 1,003

Location: Netherlands

Occupation: Web developer

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6

Sunday, March 7th 2010, 11:12pm

Image quality and compression is a hard subject indeed. It all depends on how beautiful you want to show it, how beautiful the viewer wants it, The download size of the images, the dowload speed of the viewer etc

Things you should thinks of:
-Am I going to save it as 1 jpg file or tiled. Tiled allows progressive loading. The tiles the viewer sees is loaded before the tiles in the back. But I think this is at cost of performance (constant loading vs 1 time load)
-How fast is the avg viewer downloadspeed of the viewer?
-Do you have unlimited bandwith to your desposal or does your webserver allows only a few GB. Or you within your limit?
-Artifacts you see in photoshop, don't have to be visible in the viewer because of the fov and quality filter (sharpen)
-Artifacts you see in photoshop because you are pro, dont have to be visible for the viewer
-How many colors does your file have? Usually vivid images with lots of colors, are bigger then monotome images.
-Zooming in is a nice feature. And with Feature I mean, it's a nice bonus to have. NOT a MUST! Its great for areal panorama's, but for normal street panorama's where the viewer can see everything easy, its not necessary. Using maxpixelzoom you dont go zoooming in to a pixel level. Which is ridicilous, who wants to see a 100x100 pixel car or statue. People don't care about that. Try limiting your zoom, so you can limit your number of levels a panorama has. This saves in size tremendously.

Here is some numbers from my game:
http://www.darkgfx.com/spel/index.html

Piramide location: 6000x3000. 580Kb for all the tiles together (mostly because its all brownish)
Oasis: 6000x3000: only 200kb! (because it lacks color)
Bazar: 6000x3000: 1.4mb

They are all like 10% of the size you use, but I think they still look great.
With high detailed areal panorama's, I aim for 5-8mb per photo (including all levels). With a normal panorama, 2-3mb is max. I always use like 6000x3000 resolution, sometimes 3000x1500 (because I use 3d, and that saves me render time).

You always have to have your goal (or viewers goal) in your head. What do I want to do with this panorama. Show my skills as a photographer? Or show the viewer the event thats happening (like a motorcross show or a concert). Remember it only has to look good at fov 90 ish, not all the way zoomed in. For example, you make a panorama of a fire that happened in your neighbourhood. People just wanna see the fire, not the pixel of debris falling down in highsharp gigapixel quality. Most users on krpano tend to focus too much on quality instead of the message that needs to be told ;p