On 22/03/2012 11:46 PM, Peter Jason wrote:
I have Win7 SP1. I take pictures of about 4 MB with a good quality
camera. These are excellent, but I lose definition when these are
reduced to about 500KB with software such as Photoshop. When I take
small pictures with the camera the quality/definition is very good. I
don't want to take two shots of everything just to be able to get
small pictures for emailing. Why cant large quality pictures be
reduced to smaller ones - with the same definition?
Peter

Reducing image size (eg from 4000x3000 pixels to 1200x800 pixels) will
"lose definition" as you cal it. There is no way around that. Reason: a
detail that was shown with a 6x6 pixel square in the original image will
now be shown by a 2x2 pixel square in the reduced image.

You can use a a"lossless compression" algorithm, but your camera has
already done that. The original image it took was a bitmap. The built
in software converted that to the *.jpg image that you copied to your
computer.

Bottom line: unless you have good reasons to do so, do not make image
files smaller. And if you must do so, always work ona copy, never on
the original image. FWIW, I have a "working copies" folder to ensure
that I don't mess with originals by mistake. Takes an extra step to copy
the image, but worth it.

HTH,
Wolf K.