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Pic Compression and File Sizes
Posted: 2003-10-11 06:48am
by haas mark
For some reason, my computer saves images at very large file sizes, and I don't know why. For example, I just made a wallpaper that had all of about 20 colors, at 1024x768 resolution. It's 477 kb. I don't *think* it should be that big.. but anyhow.. is there a way to fix this, and if not, is there something that I can use to make file sizes smaller?
~ver
Posted: 2003-10-11 06:53am
by Hethrir
What format, and what programme are you saving it in? There should be options for JPEG compression to control size vs. quality.
Posted: 2003-10-11 07:00am
by Sir Sirius
I once had a bizarre problem with the "Save Picture As..." funktion forcing me to save all images as 24-bit bitmaps despite the original format. Are you talking about something similar?
Posted: 2003-10-11 07:01am
by haas mark
Hethrir wrote:What format, and what programme are you saving it in? There should be options for JPEG compression to control size vs. quality.
PSP 7.04. And I have particular problems with saving GIFs. JPG compression, I could deal with, if it didn't fuck up the picture past lowest compression.
~ver
Posted: 2003-10-11 07:11am
by Hethrir
hmm, that size isn't toobad...have you tried saving it as a BMP then using another programme to save it and see if it comes out a different size? Do you know what pallette you started with? If you use to 8bit colours only in the image it may have a different result.
Posted: 2003-10-11 07:38am
by haas mark
Hethrir wrote:hmm, that size isn't toobad...have you tried saving it as a BMP then using another programme to save it and see if it comes out a different size? Do you know what pallette you started with? If you use to 8bit colours only in the image it may have a different result.
No, I haven't done that......
As for the palette, I HAD to start with a full pallette. But saving as a GIF automatically reduces it to 256 colors.
~ver
Posted: 2003-10-11 08:44am
by haas mark
Another thing I forgot to mention is that my GIFs won't retain transparency in PSP.
~ver
Posted: 2003-10-11 11:12am
by phongn
That doesn't sound so bad. An uncompressed 5-bit (32-color pallete) 1024x768 comes out to around that size. What format are you using? GIF? PNG? JPEG? TIFF? BMP?
As for JPEGs, if you're doing line art it's best to ignore it. The algorithm does not work well with line art.
If GIFs aren't retaining transparency, you're apparently doing something wrong. What, I'm not sure; I don't really like PSP and have been a PS user for some time. GIF, of course, is forced to reduce to 256 colors. PNG can be 32-bit or 8-bit, depending on your options.
Posted: 2003-10-11 11:17am
by haas mark
phongn wrote:That doesn't sound so bad. An uncompressed 5-bit (32-color pallete) 1024x768 comes out to around that size. What format are you using? GIF? PNG? JPEG? TIFF? BMP?
GIF.
If GIFs aren't retaining transparency, you're apparently doing something wrong. What, I'm not sure; I don't really like PSP and have been a PS user for some time. GIF, of course, is forced to reduce to 256 colors. PNG can be 32-bit or 8-bit, depending on your options.
Actually, for gods only know what reason, I can get it to retain trnasparency in Animation Shop, but not in Paint Shop Pro. o.O And I tinkered with the general settings, and it still didn't do it right.
~ver
Re: Pic Compression and File Sizes
Posted: 2003-10-11 12:43pm
by Hamel
verilon wrote:For some reason, my computer saves images at very large file sizes, and I don't know why. For example, I just made a wallpaper that had all of about 20 colors, at 1024x768 resolution. It's 477 kb. I don't *think* it should be that big.. but anyhow.. is there a way to fix this, and if not, is there something that I can use to make file sizes smaller?
~ver
How are the colors distributed on the image?
Are there vast areas of one color, or are there unique colors every few pixels?
Posted: 2003-10-11 04:28pm
by phongn
verilon wrote:phongn wrote:That doesn't sound so bad. An uncompressed 5-bit (32-color pallete) 1024x768 comes out to around that size. What format are you using? GIF? PNG? JPEG? TIFF? BMP?
GIF.
If you want to use palette-based format, you probably won't get much better than 480KB or so. Try enabling LZW compression for GIF images if you can, or mess with PNGs.
Posted: 2003-10-11 09:03pm
by haas mark
Posted: 2003-10-11 09:04pm
by haas mark
phongn wrote:verilon wrote:phongn wrote:That doesn't sound so bad. An uncompressed 5-bit (32-color pallete) 1024x768 comes out to around that size. What format are you using? GIF? PNG? JPEG? TIFF? BMP?
GIF.
If you want to use palette-based format, you probably won't get much better than 480KB or so. Try enabling LZW compression for GIF images if you can, or mess with PNGs.
Uhm.. what exactly is that?
~ver
Posted: 2003-10-11 10:10pm
by aerius
Shrunk it down to about 180kb with Photoshop, it's now a jpeg. Quality seems decent and I have the jpeg set at medium quality so I can squeeze it down a bit more if needed.
http://members.rogers.com/tlin0252/vnvnation.jpg
Posted: 2003-10-11 10:16pm
by haas mark
Cool.. Though it still boggles the mind why it's so big.. I don't understand why, as I've seen more complex wallpapers with smaller file sizes..
~ver
Posted: 2003-10-11 10:25pm
by Drooling Iguana
I got the filesize down to 387k by converting it to PNG.
here's the converted image (it's on Angelfire, so you'll probably have to copy/paste it to your URL bar to get it to work). I don't think you're going to get it much smaller than that.
Posted: 2003-10-11 11:15pm
by Hamel
No wonder that's a huge size in gif
Since there are no large areas of a single color, your program can't keep the file size down
Posted: 2003-10-11 11:29pm
by phongn
Indeed. There's virtually no pattern to the image that can be easily identified, and the text area is rather difficult to compress.
PNGCrush got it down to 340-350KB or so, but that's about the best lossless compression possible.
Posted: 2003-10-11 11:33pm
by haas mark
OK thanks.. but other files (like a 100x100 JPG) I also have problems saving at less that about 10-20Kb at times without losing how it looks.
~ver
Posted: 2003-10-11 11:49pm
by phongn
verilon wrote:OK thanks.. but other files (like a 100x100 JPG) I also have problems saving at less that about 10-20Kb at times without losing how it looks.
That's a 100x100 JPEG, not a 1024x768 JPEG. Also, we have no idea what the content of the two images may be. You can't simple say "this is a JPEG, it should look virtually lossless when compressed."
You have to compare on a case-by-case basis with the general compression method in mind and then choose what format to use (along with other constraints such as filesize and such).
Posted: 2003-10-12 12:27am
by haas mark
phongn wrote:verilon wrote:OK thanks.. but other files (like a 100x100 JPG) I also have problems saving at less that about 10-20Kb at times without losing how it looks.
That's a 100x100 JPEG, not a 1024x768 JPEG. Also, we have no idea what the content of the two images may be. You can't simple say "this is a JPEG, it should look virtually lossless when compressed."
You have to compare on a case-by-case basis with the general compression method in mind and then choose what format to use (along with other constraints such as filesize and such).
Well, I mean that it gets really blurry and just fucked up in general. I have ten tons of problems, it seems, with my comp and compression.. and for some reason can't run PS that's better than 6.0.
As well, that's not just 100x100 JPGs.. JPGs in general.
~ver
Posted: 2003-10-12 12:38am
by phongn
It may be that PSP's JPEG engine is not very good, but at high levels of compression you should expect macroblocking.
Posted: 2003-10-12 04:48am
by Hamel
Irfanview has a nice (this is only IMO) jpg compression going for it
If i'm working on a sig, I just save the layered file, c&p a flattened version over to Irfanview and take care of it from there
Posted: 2003-10-12 05:06am
by Einhander Sn0m4n
Hamel wrote:Irfanview has a nice (this is only IMO) jpg compression going for it
If i'm working on a sig, I just save the layered file, c&p a flattened version over to Irfanview and take care of it from there
You forgot about IView's EXCELLENT PNG Compression Engine! Check the filesize on
These Three Files.
Posted: 2003-10-12 02:12pm
by phongn
I usually use Adobe's ImageReady for making PNGs, since I can fine-tune it. Afterwards, I might use PNGCrush to see if that can do any better.