Insert awesome title here
We all know how the lossy compression that is JPEG has prompted the growth of many an HBer. PNG is a lossless compression, one that is in fact more effective than JPEG anyway. As things move over to PNG, should we see less of the old anomalies coming up?
Order of Kilopi
Probably not because they are already out there and will continue to be milked by people like Hoagland.
Established Member
No, they will convert the JPEG to PNG and claim that still there are artefacts.
I can already see the 30 page thread in which we try to explain that converting the garbage JPEG into PNG does not work and that it has to be converted to PNG from the original uncompressed file...
Established Member
Or they'll claim that the artefacts were removed in the PNG files and the JPEG files are the ones we should be analysing....
Order of Kilopi
Most spacecraft release their data in uncompressd, calibrated, IMG format. However - due to onboard compression one is still able, sometimes, to see compression artifacts in these calibrated pieces.
Face facts - a true member of the hoaglanderati will never stop trying to find nonsense at the limits of resolution.
Doug
Established Member
I wouldn't worry. There are plenty of opportunities for misinterpreting images, even when they're stored in a lossless format
Banned
Yeah im still laughing about the "tracked vehicles" and "lichen growth" found by some. If anything i think that will be used to claim that their "discoveries are More Accurate" as noone can claim its just an Artifact of compression anymore. They will see whatever they want to see, whether its a pile of rocks, some ice, or a compression artifact.
Order of Kilopi
Tracked Vehicles and Lichen growth? Try rock sheep....
Banned
Rock sheep?!?!
It's time to put my plan into action...
Order of Kilopi
I liked the Moon Dinosaur best
Order of Kilopi
Rock sheep?!?!
For those that no longer value their sanity
Order of Kilopi
[HBMode]Uhh hellllooooo... PNG is the default file type for photoshop, so anything that's in that format has been altered.[/HBMode]
I don't think it will solve anything.
I'm Not Evil.
An evil person would do the things that pop into my head.
Order of Kilopi
When I first saw that guy's rock images I really thought it was a joke. It took awhile before I realized he really did think there were Martian rock sheep, apes in suits. coins, little pyramids, insects, fossilized stingrays, and all manner of other made objects or creatures in those images.Originally Posted by PhantomWolf
I say there is an invisible elf in my backyard. How do you prove that I am wrong?
The Leif Ericson Cruiser
Established Member
Question:
What is the PNG you all speak of? I never heard of it.
Established Member
It's a graphical file format which is used when quality of images is important. Since JPG is a lossy compression format it's great for use in environments where quality is not an issue but storage space or transmission latency is an issue (like the Internet), but pretty lousy if you want to ANALYZE an image with computer tools, so PNG is a standard format for such circumstances...
Last edited by Sigma_Orionis; 2007-Jan-29 at 09:33 PM. Reason: Editted for clarity
Administrator
\HB mode\
I'm sure NASA and the evil govment just came up with PNG to hide THE TRUTH!
Seriously, people "see" all kinds of things (UFOs and such in the clouds, for example) directly with their eyes, with no compression losses at all. I suspect HBers will be finding sheep and starfish among the rocks on Mars.
Established Member
Heh heh heh, that of course means that the whole Open Source movement is controlled by the Evil Illuminati/Alien Lizards/Templar Knights what-have-you.......\HB mode\
I'm sure NASA and the evil govment just came up with PNG to hide THE TRUTH!
Seriously, people "see" all kinds of things (UFOs and such in the clouds, for example) directly with their eyes, with no compression losses at all. I suspect HBers will be finding sheep and starfish among the rocks on Mars.
Established Member
Been listening to Bill Gates, have we?Heh heh heh, that of course means that the whole Open Source movement is controlled by the Evil Illuminati/Alien Lizards/Templar Knights what-have-you.......
Established Member
Not really, just to Steven BalmerBeen listening to Bill Gates, have we?
Last edited by Sigma_Orionis; 2007-Jan-30 at 03:48 PM. Reason: Editted for clarity
Banned
Or that PNG really stands for "Protecting a Neutral Government" and that it was actually designed to automatically detect and electronically cover up any artifacts, even if converted from the original negatives...
Established Member
Hmmmm, IIRC THAT PNG was developed by the Undisclosed Government Agency which of course also handles the MIBs and is the Secret Government (TM) office that handles all Extraterrestial Affairs (including the "we will welcome our new Evil Orion Overlords Masters" treaty with Alpha Orionis......) and yes Steven Ballmer is one of them
Insert awesome title here
The w3c recommends PNG over GIF. I've certainly found that PNG's give higher quality images in smaller files. According to Wikipedia, as far as JPEG goes, it's better for photo type stuff, when you want the image a reasonable size, but PNG is better for images with text. I prepared a flowchart for my boss on Visio and then produced a JPEG and PNG from it. The PNG was slightly smaller with a higher quality.
Established Member
The reason PNG is preferred over GIF (originally anyways) is that Unisys (which holds the patent on the Lempel-Ziv Algorithm) started to charge royalties over the use of LZ (which is used by GIF), so as a response PNG was developed. Since those days GIF is becoming less and less used and a lot of development effort has gone into PNG so I am not surprised that nowadays PNG is technically superior to GIF.
Editted to add: Actually Unisys owns the patent on a VARIANT of LZ which is called LZW and that is the compression used by GIF
Last edited by Sigma_Orionis; 2007-Feb-07 at 03:22 PM. Reason: Editted for Clarity
Established Member
Well, PNG is a losless compression which works up to 48-bit colors, whilst GIF can support (only) 256 colors and JPEG is lossy. It doesn't suprise me that a losless format that supports transparency is becoming more interesting than the other two. Of course, PNG isn't as supported as the other two.
In short, PNG seems to be the ideal image format; despite that I often use GIF images too, when I use less than 256 different colors.
Order of Kilopi
PNG is a better format for synthetic graphics such as buttons, backgrounds, and other bitmap graphics that typically incorporate into web design.
JPEG is still a better format for encoding natural photography, as a reasonable compromize between fidelity and image size. Strictly speaking, DCT compression is lossy. JPEG (or more properly, JFIF) files are not required to use that compression method, or any compression method. But DCT compression works well for natural photography. Lossless compressors are within the JPEG standard, although they are not widely used. JPEG is used synonymously with JFIF interchange standards and with the DCT compression.
Insert awesome title here
That's what I said. I originally used gif's for the next/prev buttons on my website. Since I started using CSS buttons, I made a version with a gold effect backdrop to the image for hovering, to make it look nice. I first used gif and it looked crude. Then I changed to png. Not only did it look better, but the file was smaller.
Order of Kilopi
I'm not at all surprised. GIF implements transparency as a "magic" color index that applies wholly to a pixel. PNG, I believe, uses an actual alpha channel so that a pixel may be partly transparent.
For very small images (e.g., web site buttons) any gain achieved through compression is frequently lost -- and then some -- to overhead for the compressor.
Insert awesome title here
On that note, how do you put in transparency?
Order of Kilopi
The paint programs I use (Photoshop, GIMP) allow you to specify the background when creating new documents -- specifically they allow "transparent" as one of the choices. Then if you configure all your tools to use anti-aliasing, the alpha channel should preserve partial transparency at the edges of your painting.
Order of Kilopi
What hardware is required to use "alpha channel"? I have an old
computer and video card, but I do have it set to 32 bits. That is
24-bit color, and the remaining 8 bits are apparently unused. I do
not have photoshop or any other graphics program which deals
with alpha channel. I have made PNG images with the same kind
of transparency GIFs allow. I suspect that some Flash animations
I see use alpha channel, possibly via DirectX. The version of
DirectX I have is 6.1a (4.06.03.0518).
-- Jeff, in Minneapolis
http://www.FreeMars.org/jeff/
"I find astronomy very interesting, but I wouldn't if I thought we
were just going to sit here and look." -- "Van Rijn"
"The other planets? Well, they just happen to be there, but the
point of rockets is to explore them!" -- Kai Yeves
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