Printable View
I'm mostly using .png format images for my characters and other assets for its alpha channel.
Because mmf2 stores the images in the active object, is it worth compressing png files, does the mmf active translate to its own format anyway?
So, is it worth compressing .png files?
Portable Network Graphics itself is a compressed picture format smiliar to .jpg, Iv'e created most of my graphics in the built in picture editor and I have no idea what format they are stored as, i'd imagine you'd have absolutely no problems at all with .png's.
Thanks for your heads up Dragonguy.
The reason I'm asking is I used to use a little tool called PNGMonster, which compresses the image further, when I used other game engines.
But because mmf keeps the images stored in an active object, I'm wondering if it would make any difference.
I guess I could create two libraries; one with the original images and one with the extra compression, and check their sizes.
It doesn't make a difference. MMF2 stores the graphical data in it's own way.
Ahh, great thank you Nifflas.
I think MMF2 stores graphics in some RLE compressed format (similar to TGA files).
And BTW, JPG files and PNG files couldn't be further apart from each other. PNG is lossless, it will compress as good as it can as long it doesn't change a single color value. The main idea in JPG is to remove quality in order to make it take up less space.
So what your saying Andos is that .png good, .jpg bad.
Uhm.. it's really not that simple.
It's a bit like cars and airplanes. You can't say one is the better. Try to take off with a car, or try to find a runway to land on when you fly your airplane a few kilometers to visit a friend.
Lossy compressions can decrease the size of an image in ways that lossless compressions can never get near (there are a few exceptions though, for example images with large solid colour areas).
Lossless compression at the other hand doesn't mess with the image quality, so you more or less have to use it when you're still in the process of creating or modifying the image, to not lose further image quality everytime you open and edit it.
That's not entirely true. PNG does have a small loss, because it tends to darken all colors when saved multiple times.Quote:
Originally Posted by Andos
You're probably talking about the .png gamma correction, which most software just ignore. It's a gamma value saved with the file .png files, but it doesn't change pixel data, it only tells how the picture should be displayed, and there are not many programs that care about this gamma value since it's known to only cause trouble. Most graphics tool doesn't even embed a gamme value into the .png
The result of this is that .png's saved with a few certain graphics tools (e.g. some versions of Photoshop) can get darker when you open them in certain browsers (e.g. some versions of Internet Explorer), despite that it's still a lossless file that will look normal if you open it in a tool that doesn't bother to apply the .png gamma value. You can also use pngcrush to remove the gamma information from files, this is how I make sure png's saved in photoshop looks right on a website.
I think Firefox and IE ignores the color-profiles for PNG files to make sure that colors look the same on all platforms. It's somehow a hack because it's based on the idea that most graphics programs doesn't care about color profiles. Safari does show the images with their correct color profile, but that often leads to websites where some images appear darker than others.
PNG is often really good for small images or images that typically looks like GIF images. (low amount of different colors)
The simpler the image, the better it compresses (kinda).
JPEG images are mostly good for photographs. It removes quality where it isn't noticeable and can therefore be a much better choice than PNG.
My favorite format for photos: JPG
My favorite format for everything else: PNG
But what about other raster graphic formats, how do they fit into all of this?
.bmp - Uncompressed Standard.
.gif - Dunno.
.pcx - Uncompressed Picture stored as Text.
.tga - Dunno.
.tif - Dunno.
.blp - Dunno.
.ico - Icon.
.fnt - Font.
What?Quote:
Originally Posted by dragonguy
If you open a .pcx in Textpad, you get a list of all the colours used in the picture as an array written in 'Web Colours'.
Web colors, as in the hexadecimal #rrggbb ?
I never knew that.
PCX stores the image in a run length encoded binary format..
I just noticed Textpad doe's that to all of them lol, now I can't see any difference between .pcx & .bmp.
dragonguy: You can open any file in a text editor. What you'll see will be the Ascii representative character of each byte.
BMP is generally an uncompressed picture format or a compressed one with the simple RLE compression. BMP don't lose quality.
PCX is a compressed picture format. Generally, it loses quality and can be compared to PNG8 or GIF which are more sophisticated and recent formats.
dragonguy: *Does
Last time I checked, PCX was lossless. It supports palette-indexed images from 2 to 256 colours, and it was extended to support 24-bit images too.Quote:
PCX is a compressed picture format. Generally, it loses quality and can be compared to PNG8 or GIF which are more sophisticated and recent formats.
Even if it would only have had support for palette-indexed images, it would still be lossless (you might have to perform some lossy operations to reduce the number of colours to 256 or less, but that does still not make the format itself lossy).
TGA is the same, indexed or true colour options, uncompressed or RLEQuote:
Originally Posted by Sphax
So let me get this straight.
.png - Portable Network Graphics - Lossless Quality, Maximum Compression.
.jpg - Lossmore Quality, Maximum Compression.
.bmp - Bitmap - Lossless Quality, No Compression or RLE, True Colour or Indexed.
.pcx - Lossless Quality, True Colour or Indexed.
.tga - True Vision Targa - Lossless Quality, No Compression or RLE, True Colour or Indexed.
.tif - Dunno.
.blp - Dunno.
.gif - Animation.
.ico - Icon.
.fnt - Font.
.vxl - Voxel.