Re: [SLUG] BIG IMAGES
On 13 Mar 2003 18:44:49 +1100 James Gregory [EMAIL PROTECTED] wrote: Hi all, I have some images, they are gifs, and they're approximately 14000 pixels square. I'd really like to view them, and ideally perform transformations such as scaling to a less insane size. I suspect the problem is the uncompressed size Assuming they're 24bit, that's 14000 x 14000 x 24/8 = 588,000,000 bytes i.e. ~ 588 Mb. So you might need a Gig of RAM to work on them. A quick search for a image slicer only turned up windows shareware ... but surely there is something for Linux out there somewhere. Matt -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
Re: [SLUG] BIG IMAGES
On Thu, Mar 13, 2003 at 09:35:16PM +1100, [EMAIL PROTECTED] wrote: On 13 Mar 2003 18:44:49 +1100 James Gregory [EMAIL PROTECTED] wrote: Hi all, I have some images, they are gifs, and they're approximately 14000 pixels square. I'd really like to view them, and ideally perform transformations such as scaling to a less insane size. I suspect the problem is the uncompressed size Assuming they're 24bit, that's 14000 x 14000 x 24/8 = 588,000,000 bytes IIRC, gifs are 8 bit (or less). i.e. ~ 588 Mb. So you might need a Gig of RAM to work on them. So this would be ~196 Mb. You might still need alot of RAM, though :) -Andrew. -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
Re: [SLUG] BIG IMAGES
On Thu, 13 Mar 2003 [EMAIL PROTECTED] wrote: On 13 Mar 2003 18:44:49 +1100 James Gregory [EMAIL PROTECTED] wrote: I have some images, they are gifs, and they're approximately 14000 pixels square. I'd really like to view them, and ideally perform transformations such as scaling to a less insane size. I suspect the problem is the uncompressed size Assuming they're 24bit, that's 14000 x 14000 x 24/8 = 588,000,000 bytes i.e. ~ 588 Mb. So you might need a Gig of RAM to work on them. A quick search for a image slicer only turned up windows shareware ... but surely there is something for Linux out there somewhere. libungif, formerly known as giflib might be what you need. ftp://ftp.ayamura.org/pub/graphics/ has copies of both of them, wheras they seem to be gone from the primary site. Could be patent problems? There's a bunch of utilities in there which require limited memory. eg gifrsiz to resize (by simple deletion of pixels I think rather than averaging over an area). Also gifburst which will segment the image into smaller ones. Incidentally, the main LZW patent expires in June this year. Andrew -- Andrew McNaughton In Sydney and looking for work [EMAIL PROTECTED] http://staff.scoop.co.nz/andrew/cv.doc Mobile: +61 422 753 792 -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
Re: [SLUG] BIG IMAGES
On Thu, 13 Mar 2003, Andrew Bennetts wrote: IIRC, gifs are 8 bit (or less). i.e. ~ 588 Mb. So you might need a Gig of RAM to work on them. So this would be ~196 Mb. You might still need alot of RAM, though :) That's an 8 bit pallette size, where each pallette colour can take any 24 bit color value. So yes a program could store only the 8 bits needed to identify which colour from the palette is used for a given pixel, but many programs will expand it out to 24 bits in memory. Plus scratch memory used in any transformation which might be substantial as well. It all depends on the implementation. A smart program could do a scaling operation without storing the original image in uncompressed form at all, and only ever storing part of the resulting image in uncompressed form. It would cost a little in performance, but potentially not very much. Andrew -- Andrew McNaughton In Sydney and looking for work [EMAIL PROTECTED] http://staff.scoop.co.nz/andrew/cv.doc Mobile: +61 422 753 792 -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
Re: [SLUG] BIG IMAGES
On Thu, Mar 13, 2003 at 06:44:49PM +1100, James Gregory wrote: Hi all, I have some images, they are gifs, and they're approximately 14000 pixels square. I'd really like to view them, and ideally perform transformations such as scaling to a less insane size. What can do this? I suspect part of the problem is that the gif needs to be decompressed. If someone can suggest something that will convert a gif to something else for big files, that would be a great start. Programs that crash so far: gimp gqview convert eog have you tried giftopnm | pnmscale 0.1 | pnmtopng ? They don't seem to use a lot of memory (~1M), I use them to manipulate scans and faxes which are moderately big. cheers, Woody -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
[SLUG] BIG IMAGES
Hi all, I have some images, they are gifs, and they're approximately 14000 pixels square. I'd really like to view them, and ideally perform transformations such as scaling to a less insane size. What can do this? I suspect part of the problem is that the gif needs to be decompressed. If someone can suggest something that will convert a gif to something else for big files, that would be a great start. Programs that crash so far: gimp gqview convert eog Thanks, James. -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
