On Sat, 02 Feb 2002 20:08:19 -0800, Sid Barras wrote: > ><<I see a 600x410 picture with a size of 26K. >Didn't you say that you sent 75K? >Perhaps this accounts for your artifacts.>> > >I suppose this is going over my head when we begin to talk about jpeg >compression, but is my file size is 74k when closed, and stored on the >server, does it suddenly take up more space on the server when it is open? >
No, not on that server (or whereever your hard-disk storage is). What happens if you open a compressed image (like a .JPG) is that it is uncompressed in the computers memory. If you have made an image that has 600x400 pixels, it will be exactly 720.000 bytes in memory (600 * 400 * 3, where the 3 is 3 bytes resulting from using 24 bits color) (and each byte holds exactly 8 bits :-) So this 720.000 bytes is almost 10 times bigger (arround 700Kb) than allowed for the PUG, that is why you will use the JPG file format to store it in, that will reduce the size of the file on DISK (and internet and ...) by using compression. That will reduce the quality of the image a bit but could size it down to something like 75Kb in this case. The size that is shown in the statusbar of your graphic manipulation program (like photoshop) is probably the uncomressed size (720.000 bytes here). >So, the actual image must be under 75k when it is open? No, if you would do that you reduce the number of pixels (resolution). 75Kb open, would be something like 130x200 pixels. (130 * 200 * 3 = 78.000 bytes) If you would save such a file as a JPG it would be much smaller, possibly even below 10Kb. (or maybe the 26Kb mentioned before). What I do for PUG submissions is scale it down in Photoshop (or other image program) to an image of 600x400 pixels, then add a signature-text and save it as a TIFF format. This results in a file probably arround 500Kb. Then I save it AGAIN as a JPG, just for use on the WEB (PUG). I select JPG compression such that the resulting diskfile will be 75Kb or slightly less. Most image programs let you select that by trial-and-error without actually saving the image. Once the resulting size shown is within limits, you let it save it ... >And one last puzzlement, why isn't the code for the page written so that >the thumbnails will show in both netscape and explorer? It used to be, but Netscape keeps changing :-) BTW: I use Netscape 4.61 without any problem. Regards, JvW --------------------------------------------------------- Jan van Wijk; www.fsys.demon.nl - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
