Game resolution

[HumbertTheHorse]

png is the way to go. It holds alpha, can be opened in web browser and is lossless, even with compression. Jpeg compression of an 800x600 image upscaled is quite noticeable and even more so with anime style images (solid colors and lines).

[AxemRed]

Jpeg compression of an 800x600 image upscaled is quite noticeable and even more so with anime style images (solid colors and lines).

Depends on the JPEG quality, try 95+% quality with no chroma subsampling. Using a higher game resolution reduces/removes the need for upscaling, letting you can get away with lower quality settings.

[papillon]

pngs are nice, but can lead to filesize whoa. I shake my fist in frustration at people who insist on doing Let's Plays with a png screenshot for every line of dialog. page takes forever to load and the memory use chokes my browser!

But yes, we were talking about having images prepared for multiple sizes, NOT upscaling the jpgs.

[Blane Doyle]

Papillon, I think part of the reason that a lot of photo LPs are done in PNG is because, unless you have something better than the super basic Windows Paint or know how to work with it... JPG looks like shit when you save it, honestly. Artifacts EVERYWHERE.

You really only have PNG , JPEG, TIFF (do people use this?), GIF (which almost no one seems to use in my experience) and an array of Bitmaps. Even if the file size is larger, they take the default/better looking option simply because it looks better/is less work for them.

Granted, I am only speaking because of experience talking to a couple of these people, but I am assuming they were not the only ones who thought like this.

As for downloading larger games, I wish it was easier to make and distribute/more popular to create torrents. The few free games I have downloaded through them have been amazingly convenient.
My net cuts out for 3 seconds? It doesn't have to restart and it keeps on truckin'! I use good ol' MediaFire? TROLOLOLO GOTTA START OVER.
My internet connection hates me sometimes, I swear it does. If every free game here had a torrent, it would be like Christmas to me. (Granted, I know not everyone likes Torrents, but it floats my boat well.)

[tigerkidde]

I think I'm missing something big, but can jpeg be transparent? I don't think I've tried in six years due to failure to implement, but if such is the case...

I think for the developer, it may be based on the resolution they are comfortable with. I have been using the 800x600, because 1024x768 starts to go off my laptop screen at a resolution I can see and use. If I go higher and mess with the DPI or other font settings, some menus and buttons on programs I use become inaccessible.

But if on the image management side, if I could cut down on file size, I think that might help better on locations with slower internet connections. This thread has given me much to ponder.

[HumbertTheHorse]

The other problem with jpegs, and all lossy compression formats, is the effect on quality of compressing an already compressed image. Jpeg compression works badly on jpeg artifacts. If you must fit your game on a 5 1⁄4-inch floppy, convert the png to jpg only after you are sure it won't be touched. And keep the png just in case.

[Desu_Cake]

I just had a lecture on this this morning, so forgive me if I ramble.
JPEGS exist for the sake of photographs. Any photo that you take will have huge amounts of different colours, even in an area that appears monochrome. This means that the lossless compression algorithms used by GIF and PNG(Which work on large blocks of colour and repeating patterns) are basically useless, you'd get almost no compression at all. JPEGS use an incredibly complicated algorithm to work out which colours will be missed least and removing them.
Hence, anything created in a computer ought to never be saved as JPEG, since even with the messiest art you can create, it will never be as messy as a photograph, so lossless compression should have at least some effect.

[Ziassan]

Okay, but making a game, when one have to choose between a 1.5mo PNG or a 300ko JPG as background without notable difference to the eye... that's not even about a choice, it's for the sake of the user.

Same goes with music - as musician I feel bad to say it and audiophiles will hate it, but 192~224kbit/s is far enough if caring about filesize. Vast majority of the population don't really tell the difference between some 192 and some 320 seriously.
I said that somewhere else, but even in the famous Umineko VN also well-know for its music, most of the tracks are in 192kbit/s.

.. well it's becoming to look quite like another thread called "optimizing assets" or something like that

[HumbertTheHorse]

The Walking Dead Game episode 1 received many complaints about the level of compression used on the sound. People were irate that the developer compromised the audio quality to reduce the download footprint. They quickly released a patch that switched out the audio with a less compressed version.

Don't piss off the ADD community. Better to have a perfect looking 800 png than a rough looking 1080 jpg. They will get over the res. (of course they wouldn't buy a VGA game to begin with. Proletariat swine!)

[papillon]

Papillon, I think part of the reason that a lot of photo LPs are done in PNG is because, unless you have something better than the super basic Windows Paint or know how to work with it... JPG looks like shit when you save it, honestly. Artifacts EVERYWHERE.

And for an actual game art, that would matter.

For a Let's Play? STOP DOING THAT ALREADY.

This complaint brought to you by someone who is tired of her browser exploding.

(Especially as I tend to think if you want to see the game perfectly you should buy the game and play it yourself.)

[AxemRed]

Comparison between JPEG and PNG

First, 800x600 PNG (600KB)

800x600 PNG

Then, 1920x1080 JPEG (578KB)

1920x1080 JPEG

For reference, 1920x1080 PNG (2.31MB). I could not tell the difference with the JPEG version at 1:1 scale, normal viewing distance.

1920x1080 PNG

Code: Select all

nvimgdiff test1920x1080.jpg test1920x1080.png
Image size compared: 1920x1080
Total pixels: 2073600
Color:
  Mean absolute error: 1.034654
  Max absolute error: 40.000000
  Root mean squared error: 1.631223
  Peak signal to noise ratio in dB: 43.880535

If the filesize is the same, I'd rather be playing the 1920x1080 JPEG version.

[nyaatrap]

I think I'm missing something big, but can jpeg be transparent? I don't think I've tried in six years due to failure to implement, but if such is the case...

It can. http://www.renpy.org/wiki/renpy/doc/cookbook/JCC

I think for the developer, it may be based on the resolution they are comfortable with. I have been using the 800x600, because 1024x768 starts to go off my laptop screen at a resolution I can see and use. If I go higher and mess with the DPI or other font settings, some menus and buttons on programs I use become inaccessible.

1024x640 is the best resolution for laptop users who is playing in window mode. I don't know why people don't develop their games in this resolution.

Proper jpeg compression requires experience and knowledge. Even many professionals don't know how to compress into jpeg effectively. At least knowledge of chroma subsampling and tools which have an option to manage it are required.

[HumbertTheHorse]

And now the worse case scenario, Taken from our beloved wikipedia:

Illustration of the effect of JPEG compression on a slightly noisy image with a mixture of text and whitespace. Text is a screen capture from a Wikipedia conversation with noise added (intensity 10 in Paint.NET). One frame of the animation was saved as a JPEG (quality 90) and reloaded. Both frames were then zoomed by a factor of 4 (nearest neighbor).

[AxemRed]

Proper jpeg compression requires experience and knowledge. Even many professionals don't know how to compress into jpeg effectively. At least knowledge of chroma subsampling and tools which have an option to manage it are required.

For the images I made, I only fine-tuned the quality to match the 600KB filesize of the PNG. You can change some other settings when compressing to JPEG, but they rarely gain more than 5%.

Illustration of the effect of JPEG compression on a slightly noisy image with a mixture of text and whitespace.

I'll keep that in mind next time I'm making a 480x270 (to achieve the 4x zoom) visual novel using monochrome rendered text for a background. My point is -- that's not a realistic example for our current discussion.

Your example also appears to be created by a very crappy program. Using the same procedure, 90% quality in Photoshop:

Jpeg-text-artifacts-90.png (8.25 KiB) Viewed 2739 times

[nyaatrap]

In before, don't use jpeg on images made with vectors like texts. That's almost meaningless to reduce file size.

Subsampling is really important on skin colors and high-value red. I'm an artist and I can see jpeg compression noises on my paintings, even in no subsampling with 100%. It annoys me a bit and when I use 4:2:1 or such subsampling... I can't bear with it. But whatever, if they're not my art and compressed them carefully, I may not care much.