Ive run into a 'problem'. Basically, my game is a broken sword type adventure game. For this reason, it contains LOTS of large images (as backgrounds). I want to allow the biggest userbase I can, so Im giving the option of running the game in 800x600 and 1024x768. However, I dont want to resize EVERY image either up or down to fit the user's resolution. Should I provide two downloads (one Hi-res and one Low-res). Should I just make the download huge and have both images incorporated so I just load the selected one. Or do i sell it CD-ROM based?
thanks

For the full version, I think it would be a mistake to split it into low res and hi res. If I buy a game online, I expect to have all of its capabilities, and not to have to decide if I'm going to play it at one res or the other. You could always offer a CD for the people that have a problem downloading the file.

How big is this exactly?

Well, I havent started much but I want to know in advance how im going to sell it so that I dont have to go back an implement new features. (Ive already got my plan sorted out)

My suggestion would be to first make sure you are using the best compression options (for example, try jpg and jpeg2000 if it's appropriate).

Then, I would only store the 1024x768 and get a good image library to do a high-quality resize down to 800x600.

Maintaining multple versions of the game will just turn into a big headache...especially any time you need to make an art change to the backgrounds.

If you make a CD-ROM version available, use the original uncompressed art (which can be used as an upsell feature to buy the CD-ROM).

Good luck,
-Scorpio

thanks. I was thinking of using BMP for the background and PNG's for mostly everything else. Im wary of using JPEGs after the recent law suits. Doesnt affect us now, but still....;)

Since BMP and PNG are both lossless, but BMP is and uncompressed format...why not use PNG for the backgrounds too?
-Scorpio

Originally posted by Reanimated
thanks. I was thinking of using BMP for the background and PNG's for mostly everything else. Im wary of using JPEGs after the recent law suits. Doesnt affect us now, but still....;)
What law suits?

[edit] Alright, I Googled it up. Bastards.

I thought BMP quality was better than pngs? :rolleyes: lol thanks for the early warning, at least I wont have to change too much :P

As for the lawsuit, heres a link:
JPEG PATENT (http://p2pnet.net/story/1294)

so many huge companies being sued.

I recommend PNGOUT:
http://advsys.net/ken/utils.htm
Be sure to read the tutorial and use /f0 if you want to get a lossless image (adaptive is slightly lossy and the default for true color images).

Note that these lawsuits are mostly aimed at big software companies that write out the jpg format. Just reading it into your game is probably not going to be a problem.

(on the other hand, who knows what could happen down the road :)

-Scorpio

Originally posted by oNyx
I recommend PNGOUT:
http://advsys.net/ken/utils.htm
Be sure to read the tutorial and use /f0 if you want to get a lossless image (adaptive is slightly lossy and the default for true color images).

ONyx, just to be clear, are you saying that there is a PNGOUT option that is lossly? My understanding is that that's not the case (ie, the image output is always lossless) ...but I'd like to be sure. Thanks.
-Scorpio

OptiPNG (http://www.cs.toronto.edu/~cosmin/pngtech/optipng/) is another good route for optimizing PNGs. Most benefits of optimization only apply to palletized PNGs, though--true color PNGs won't shrink much.

And in regards to file size, the anecdotal information I've collected over the last year is that there are three cutoff points:

2MB
8-10MB
180-200MB

Statistically, these are the significant spikes for incomplete downloads. What they mean is that if you have a 4MB game, you could grow to 6-8MB without seeing a significant increase in downloads. Likewise, a 100MB game could expand to the next cutoff point without another huge jump in failed downloads.

Of course, smaller is always better, and size certainly affects whether or not someone even starts the download in the first place. Just thought I'd pass these numbers on (heard them slightly differently from multiple sources--Real, Shockwave, Trymedia, etc).

Originally posted by Scorpio
ONyx, just to be clear, are you saying that there is a PNGOUT option that is lossly? My understanding is that that's not the case (ie, the image output is always lossless) ...but I'd like to be sure. Thanks.
-Scorpio

PNGOUT uses senseful default switches, wich makes perfect sense in 99% of the cases.

E.g. no filter for indexed images, but it uses adaptive filtering for RGB input files by default. However, I couldn't see any degeneration in quality, therfore I won't mind that.

You can run some tests if you like with /f0 (filter: none) and /f5 (filter: adaptive). And then just compare 'em in your favirite drawing programm (layer one over the other and use difference, then merge and use the "magic wand")

Originally posted by oNyx
[B]PNGOUT uses senseful default switches, wich makes perfect sense in 99% of the cases.

I'm just trying to figure out if it's lossy or lossless. I understand that a person may not be able to tell the difference. My understanding was that PNGOUT was still always outputing a lossless image (ie, the input is still the exact same as the output in terms of the pixels that make up the image).

However, it seems that you are saying that the /f5 filter may/will result in a lossy image. Is this correct?

In summary, my question is simply: Does the /f5 filter produce a lossy image (i.e., it's not 100% the same as the input)

Thanks for the clarification...
-Scorpio

>Does the /f5 filter produce a lossy image
>(i.e., it's not 100% the same as the input)

As far as I can tell... it can produce a slightly lossy image, but all my test images are pixel identical.

However, it won't result in visible artifacts and if you really want to ensure that it's lossless use /f0.

edit: For clarification - PNG itself is of corse lossless. It's the prefiltering wich can create a minor divergence (something like +/-1 for some pixels).

Originally posted by oNyx
>Does the /f5 filter produce a lossy image
>(i.e., it's not 100% the same as the input)

As far as I can tell... it can produce a slightly lossy image, but all my test images are pixel identical.

Ok. Well, since everything I've read doesn't say anything about lossy, and all your tests come out lossless, I'm going to keep assuming it's lossless. :)

Thanks for the extra info.
-Scorpio

I use ULead PhotoImpact (it's really cheap, got version 7 back then for about 70€) for writing highly optimized png Images.

In my experience it has one of the smartes png saver/optimizer. Of course as someone mentioned - png by itself is lossless, but with some sorts of preprocessing the image could be optimized in a way which enables better compression.

What makes PImpact so usefull is the preview while chosing/optimizing png options. It's a double view pane showing the original image as well as the optimized and its size in bytes so one can drag around sliders and change options until everything's fine.

Regards,

Michael