On 2 Jul 2002 at 14:06, [EMAIL PROTECTED] wrote: > Ihave been following this thread and have been very interested. One of the > reasons I have not submitted to PUG has been the hassle of getting an image to > the right size for submittal.
It seems that one of the common problems for people new to digital image production is the confusion that lies in the difference between scale (dpi) and image dimensions (pixels) and their effects on the target display media. Print media generally benefits from a higher resolution than is required for screen display and good print software generally makes use of scale information that is embedded in an image by the scanner software. For example when a 35mm film is scanned full frame at 4000dpi (3780 x 5670 pixels) and then printed without re-scaling using a scale sensitive application than the resultant image on the output media should reproduce at 24mm x 36mm in size. Most web browsers are resolution dependent (however they can scale), they display an image based on its image dimensions in absolute pixels (times a scaling factor if it is specified). You can assume that the screen as an output media has a resolution of about 72 dpi (to find your actual screen resolution divide horizontal display screen area setting by the visible desktop width in inches) so you can assume that in most cases an image of 600 pixels by 400 pixels will display about 8.3" x 5.5" on the average screen (without browser scaling). If the 400dpi film scan mentioned above was displayed in a regular browser on a regular screen without resizing the image would display virtually 52.5" x 78.75" Obviously in this case using an average computer there would only be a very small portion of the image visible in the browser at any one time and there would be a lot of scrolling going on in order to see the remainder, not desirable. What it boils down to is that some scanner software is biased towards print output and some towards screen so if you are confused at the scanning stage as to how big the file is going to be it's best to scan at the maximum resolution/size available (without interpolation ie at the scanners natural resolution) and then the resize the image using an image editor application. There are many inexpensive and capable shareware image editors such as Paint Shop Pro or commercial applications such as PhotoShop, most will allow you to resize an image with ease and also to compress your image to comply with the requirements stated in PUG submissions page. Resizing involves not just adjusting the resolution stored in the image but resampling the image in order to form an new image with fewer actual pixels in each dimension. Generally you will be able to specify the length to resize one side and the other will be resized automatically in order to constrain the image proportions. I hope this helps Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications.html - 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 .
