ZDoom

Do you like to shoot in the air?

Ooh, looks pretty cool..

Yay!!!

A new map from Rex!

Yay!


(And so on. )

Hirogen2 wrote:Do you like to shoot in the air?

I was asked the same question on the DW forums. What I'm doing is simply trying to brighten up the area a little, so that the screenshots aren't really dark. (Using the night vision goggles is not an option, as it applies maximum brightness and leaves no shadows.) The chaingun, because of it's continuous fire rate, requires the least degree of timing with the pressing of the screenshot button on the keyboard.

Rex: why not just up the gamma in the game? (either type gamma #.# in console or press F11) or in the final screenshots

there is a seprate gamma level for screenshots. so no matter how bright you make gameplay, shots will always be dark...

i forgot what the cvar was... its like "png_gamma" or something...

Once upon a time I was testing a wad, and taking copious screenshots. Unsurprisingly, they tended towards dark, so I simply opened them in PaintShop Pro, and upped the gamma by about 1.2. Also unsurprisingly, they were much more useful then.

.
It must be that every computer takes screenshots differently. The settings in my zdoom-xxxxx.ini are the default

• Code: Select all

  png_gamma=0
  png_level=5

and the screenshots are just the right brightness.

But still, if they turn out too dark, it would be a nice gesture to brighten them up before posting. And possibly
in a screensize which will not enlarge the posting area too much (800 x 600).

A nice program to do quick editing is IrfanView
.

Euh, png_level is not the compression level?

Hirogen2 wrote:Euh, png_level is not the compression level?

You are absolutely correct.
I threw that one in only, because the compression level affects the details in a png. The more it is compressed, the lossier the result.

edited footnote:
OOOOPPS: See Randy's explanation about compression a little further on. I stand corrected?
.

Kappes Buur wrote:.
But still, if they turn out too dark, it would be a nice gesture to brighten them up before posting. And possibly in a screensize which will not enlarge the posting area too much (800 x 600).

A man after my own heart. My raw .png screenshots are typically too dark (I'll might fool around with the .ini settings to see if I can fix that), so I edit them in the HP image editor that I have on my computer. I have to take care that the picture is not brightened to the point of looking washed out. Then I reduce the file size to 800 * 600 and convert the format to .jpg.

Most times I shoot at enemies while taking screenshots, so the picture gets brightened in a "natural" manner. In this case I haven't put any enemies in yet, hence the apparently insane shooting of walls.

The more it is compressed, the lossier the result.

PNGs are lossless.. I'm not sure why there's an option to set the compression level since the resultant quality would be the same. Only file sizes would be different.

The png_gamma cvar is the gamma level that gets written to the PNG file. If it's 0 (the default), then the gamma cvar (which is used for display) is written instead. Playing in windowed mode and thus looking at screenshots generally need a higher gamma than fullscreen, so that's why you can set the gamma in the screenshot to be different from the gamma in-game.

Note that the palette in the screenshot is not altered by the gamma setting. ZDoom stores the gamma level in the standard PNG gAMA chunk, and it is up to the viewer program to use that to display the image at the correct gamma level. Internet Explorer properly displays PNG gamma, but other viewers might not.

I don't remember if PCX screenshots contain gamma-adjusted palettes or not, since PCX can't hold any gamma information.

Regarding png_level, it's there so you can decide your own balance between compression efficiency and compression speed. I don't know where the idea that PNG is lossy came from, but I've seen it a few times and it is absolutely not true. PNG uses exactly the same compression scheme used in most zip archives.

Usually no, when I discovered Paint Shop Pro's PNG Optimizer:
It lets you choose whether to reduce to 8-bit, grayscale, or leave it at 16.7 million colors.
If you choose 8-bit colored, you can say how much colors you want in the final image (and how much dithering in %). For 8-bit color you can also choose a Reducing Method (Optimized Median, Optimized Octree, Web-Safe), and so on as well as transparency/alpha, and (non-)interlaced.
As you can see, it is totally up to the user to decide how to make quality; somewhat, reducing colors is "the user's fault" which means that it is not mandatory to reduce colors. You could also reduce colors before saving the file, so the result can't be lossier, whilst PNG had been designed to be a lossless codec.
Surprisingly, interlaced PNG take up more space.
Yet, after listing all those options, I do not know what the PNG compression level means any more. It seems like "set your options", fine, "set a compression level, and you will get the best result, despite your compression level".