Rick, You're half right and half wrong, or you're not explaining the other half clearly. You are correct that a 5x7 at 300dpi is bigger than a 5x7 at 72dpi. However, a 320 pixel wide image is going to be the exact same file size regardless of dpi.
DPI is a virtual measurement derived by the total number of pixels divided by the display size of the image in inches. DPI doesn't really exist, only pixels exist and the display of those pixels. A 800x600 image at 72 dpi is exactly the same as a 800x600 image at 300 dpi. They both weigh in at 1.4MB, but the 72dpi will print at 11.1"x8.3" and the 300dpi will print at 2.6"x2". The 72 dpi prints bigger just because you're stretching the same number of pixels over a larger area. And obviously, the apparent quality also goes down. But it's the same image either way. So before you try to set the display size thus dpi of the image, you need to calculate the absolute pixel sizes you're looking for. For instance: 8x10 at 300dpi = 33.3x41.6 at 72dpi = 2400 x 3000 pixels 5x7 at 300dpi = 20.8x29.1 at 72dpi = 1500 x 2100 pixels So those pixel measurements are what you are really shooting for. Size your images to those pixel values and if your tag of choice doesn't let you set the dpi, it doesn't matter that much because the end-user's software will raise the effective dpi when they make the display size of the image smaller. Many online image companies do it this way. BTW, I'd recommend thouroughly testing the image tag on a development server before putting it on your production box. The cfx_image tag crashed our server when I tried it a few years ago, but others swear by it. -Kevin ----- Original Message ----- From: "Rick Faircloth" <[EMAIL PROTECTED]> To: "CF-Talk" <[EMAIL PROTECTED]> Sent: Wednesday, September 10, 2003 11:28 PM Subject: RE: Image manipulation > I've seen that cfx_image can resize the dimensions of a photograph, > I just haven't found anything that tells me whether the tag can read > resolution (dpi) > and allow that to be adjusted... > > A photo that's 320 pixels wide is a much larger file at 300 dpi than one > that is 72 dpi... > > For example, a 5x7 inch photo at 300 dpi is a 9MB file...at 72 dpi it's > 531KB. > And since a typical computer screen can only display 72 dpi, there's no need > in > trying to display a 300 dpi photo when a 72 dpi will be more appropriate. > > Rick > > > > -----Original Message----- > > From: Doug White [mailto:[EMAIL PROTECTED] > > Sent: Wednesday, September 10, 2003 11:43 PM > > To: CF-Talk > > Subject: Re: Image manipulation > > > > > > I suggest cfx_image for resizing on the fly > > > > > > > > ====================================== > > Stop spam on your domain, use our gateway! > > For hosting solutions http://www.clickdoug.com > > Featuring Win2003 Enterprise, RedHat Linux, CFMX 6.1 and all > > databases. > > ISP rated: http://www.forta.com/cf/isp/isp.cfm?isp_id=772 > > Suggested corporate Anti-virus policy: > > http://www.dshield.org/antivirus.pdf > > ====================================== > > If you are not satisfied with my service, my job isn't done! > > > > ----- Original Message ----- > > From: "Claude Schneegans" <[EMAIL PROTECTED]> > > To: "CF-Talk" <[EMAIL PROTECTED]> > > Sent: Wednesday, September 10, 2003 10:17 PM > > Subject: Re: Image manipulation > > > > > > | >>if I want a 300 dpi image (the original) available for download, > > | >>but want to display a 72 dpi version > > | > > | What does mean "dpi" when the image has been scanned on an > > equipment you don't > > know at a resolution you don't know > > | and it will be displayed on a screen you don't know? > > | > > | Talk pixels, not dpi. All you need to know is that about > > 50% of users now have > > 1024 pix or more, and most of the rest > > | has at least 800. Within 2 or 3 years it will be 50% 1024 > > and 50% 1600 or > > more. > > | > > | > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > ~~~~~~~~| > > Archives: http://www.houseoffusion.com/lists.cfm?link=t:4 > > Subscription: http://www.houseoffusion.com/lists.cfm?link=s:4 > > Unsubscribe: > > http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=708.628.4 > > > > Signup for the Fusion Authority news alert and keep up with > > the latest news in ColdFusion and related topics. > > http://www.fusionauthority.com/signup.cfm > > > > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Archives: http://www.houseoffusion.com/lists.cfm?link=t:4 Subscription: http://www.houseoffusion.com/lists.cfm?link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Your ad could be here. Monies from ads go to support these lists and provide more resources for the community. http://www.fusionauthority.com/ads.cfm
