Picture Size (Pixels & Kb)

Hello everyone,
what is the relationship between the no. of pixels a picture has, it's
width and height and the Kb it takes up, esp. pix on the Web.

Thanks,

Fergal.

On 27 Jan 2007 13:52:17 -0800, "tallmanirl"
wrote:

Hello everyone,
what is the relationship between the no. of pixels a picture has, it's
width and height and the Kb it takes up, esp. pix on the Web.

Thanks,

Fergal.

Let me try to help you, and just ignore the smart asses on here. While
your question is very complicated here is a short response which will
probably hit what you are after.

Someone on here stated that if you divide the number of pixels by 300
that will give you a rough idea of the number and size of a good
print. For example a Nikon D200 taking a RAW image at 3872 x 2592 @
300 dots per inch and a size of 4.1 Meg would yeild a picture of 12.9
x 8.64 Also the defualt in Photshop for a Raw File of this size after
changing the Resolution to 72 is an amazing 53 x 36 inches (that even
surprised me) But after adjusting it to a resolution of 72 and
changing the size to 10 x 6.6 for the web the size is now only 227 KB

For the web you can save a picture in Photoshop with a resolution of
72 dpi and it will still look good and be only a few hundred K.
(Provided that you also change the size as well) The prefered way to
resize a picture in Phtoshop is 4 Steps

(1) In Photoshop press CTRL ALT and I (brings up size window)
(2) Uncheck Resample Image
(3) Change Resolution and Image Size (try 72 for resolution)
(4) Check and turn back on Resample Image

Save the new Picture.

Hope this answered what you were really looking to learn.

Jim Townsend wrote:
LuvLatins wrote:


For the web you can save a picture in Photoshop with a resolution of
72 dpi and it will still look good and be only a few hundred K.
(Provided that you also change the size as well) The prefered way to
resize a picture in Phtoshop is 4 Steps

(1) In Photoshop press CTRL ALT and I (brings up size window)
(2) Uncheck Resample Image
(3) Change Resolution and Image Size (try 72 for resolution)
(4) Check and turn back on Resample Image



Why not ignore the PPI completely and just resample the image
so it fits on your intended recipient's screen?

There are still many people with screens that display 1024x768 pixels.
So for the web, why not:

1 - Bring up the size window.

2 - Make sure 'resample' and 'constrain proportions' are checked.

3 - In the pixel dimensions, change the width to 800 pixels
(The height will rescale automatically to keep the aspect ratio).

That's ALL you need to do. A 800 pixel wide image will fit nicely
on most screens, but might be a little small for people with
their displays set to 1600x1200 or higher.

Monitors are fixed arrays. They care not about DPI. An 800x600 image
will look exactly the same no matter if it's 7 DPI or 7000 DPI.

When displaying images on monitors, laboring over PPI/DPI just adds
confusion to the image editing process.

Sounds familiar.

Gary Eickmeier