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.

In article . com,
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.


Zero.

--
You need only reflect that one of the best ways to get yourself a
reputation as a dangerous citizen these days is to go about repeating
the very phrases which our founding fathers used in the struggle for
independence.
-- Charles A. Beard

On Sat, 27 Jan 2007 13:53:40 -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.

If it is uncompressed, then kb = w*h*3/1024. w*h gives the number of
pixels. Each pixel is generally represented by three bytes - one each for
red,green,blue. Most point and shoot cameras will save the data as a
jpeg, with a compression ratio of between about 3 and 10. Very simplistic,
and not taking into consideration all the other factors that can intrude.
I expect you can find a fuller explanation at wikipedia.

On 2007-01-27, Ken Lucke wrote:
In article . com,
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.

Zero.

Gotta say, Ken, you're, at least, concise!

Justin.

--
Justin C by the sea.

In article m, Justin
C wrote:

On 2007-01-27, Ken Lucke wrote:
In article . com,
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.

Zero.

Gotta say, Ken, you're, at least, concise!



Well, it IS the correct answer for the question asked. There is NO
relationship between those things without many other factors being
specified.

--
You need only reflect that one of the best ways to get yourself a
reputation as a dangerous citizen these days is to go about repeating
the very phrases which our founding fathers used in the struggle for
independence.
-- Charles A. Beard

"tallmanirl" wrote in message
ups.com...
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.


Have a look at www.scantips.com for good explanation of most parts of
this stuff.

Roy G

Justin C wrote:
On 2007-01-27, Ken Lucke wrote:
In article . com,
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.
Zero.

Gotta say, Ken, you're, at least, concise!

Justin.

but concisely wrong...

Ken Lucke wrote:
In article m, Justin
C wrote:

On 2007-01-27, Ken Lucke wrote:
In article . com,
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.
Zero.
Gotta say, Ken, you're, at least, concise!



Well, it IS the correct answer for the question asked. There is NO
relationship between those things without many other factors being
specified.

So I can have a gigabyte pixel image on the web with zero bytes size?
Not too realistic, is it?

Ron Hunter wrote:

Ken Lucke wrote:
Well, it IS the correct answer for the question asked. There is
NO relationship between those things without many other factors
being specified.

So I can have a gigabyte pixel image on the web with zero bytes
size?

You're making a formal mistake here. While there might be no
relationship, you'll still have to obey the limitations of the chosen
image format.

Unless we get into the whole semi-philosophical debate about the empty
group satisfying any rules (sorry about the bad translation, english is
my second language), then all image formats takes up some bytes.


So your gigapixel image can be compressed to a single colored square,
specified as having the right dimensions and taking up a few bytes,
or it could be stored uncompress and taking up gigabytes. This would
satisfy the NO relationship clause.

Not too realistic, is it?

The problem is that it really _is_ realistic, if you only look at
megapixels. A single-colored square at gigapixel size would likely be
compressed down to a few KB using PNG (or TIFF LZW or GIF or...).

So we can't say anything, unless we have an idea of the nature of the
original image and the expected quality.
--
Toke Eskildsen - http://ekot.dk/

Justin C wrote:

Gotta say, Ken, you're, at least, concise!

And right...

174MP, 523MB: http://ekot.dk/misc/filesize/174MP.tif (photo)
174MP, 136MB: http://ekot.dk/misc/filesize/174MP.png (same photo)
174MP, 20MB: http://ekot.dk/misc/filesize/174MP.jpg (same photo)
174MP, 1MB: http://ekot.dk/misc/filesize/174MP_Q1.jpg (same photo)
174MP, 21KB: http://ekot.dk/misc/filesize/174MP_blank.png (blank)
--
Toke Eskildsen - http://ekot.dk/