Solved

# Amount of ink used or Amount of white space?

Posted on 1998-10-15
269 Views
Hi,

I would like to work out how much ink I am using per picture to work out the approximate cost. The manufacturer quotes 600 pages at 5%. But what % is in my picture?

If I turn the picture to black and white, save as a bitmap, is there an easy way to total up the number of black pixels and white pixels?

Any other ideas would be welcome.

TIA
0
Question by:alanlam

Expert Comment

ID: 1113013
Adobe photoshop : Histogram shows count ant percentage of pixels by color. If you convert your picture into 2 colors you will be able to see count and percentage of black and white pixels.
However your printer may approximate pixels differently and your image can be smaller than page.

This is VERY expensive solution unless you already are using photoshop.

Good luck
0

Author Comment

ID: 1113014
Edited text of question
0

Author Comment

ID: 1113015
It worked. Could you "answer" the question rather than "comment" so that I can give you the 50 points! :-)
0

LVL 12

Expert Comment

ID: 1113016
Take area of image as %age of page size. Figure coverage density of image as 50% (this is correct if the scene is evenly balanced and contrast follows "normal distribution". Text density is normally considered 5%. If you're using reverse cuts, then covereage for that portion is 95%. If you can get histogram of image, peak of histo will show you median density. Should be "bell curve" around 50%. If is skewed, then use higher or lower figure as %age of skew.

Converting image to binary (thresholded B/W) is poor approximation.

M

0

Author Comment

ID: 1113017
I agree that b/w is a poor approximation but the picture is a diagram with irregular solid areas of colour with large areas of white. I've turned all the major areas into dark colours, made it b/w, loaded into Photoshop and have an approximate answer.

Could Valka answer the question so that I can award the 50 points!
0

LVL 2

Expert Comment

ID: 1113018
Do you got a empty or a full Ink-cartridge? Maybe instead of trying to guessing the cost you could weigh it.
Get the weigh of the empty/full cartridge and then the weigh of the one you are using, callculate the differnece of them, this should be the weigh of the used/remaining ink in the cartridge. Now print some standard pictures and weigh the used cartridge again.
Well, this only works if have a tool to weigh exactly enough. In the school we used some electronic tools for such tasks.

0

Author Comment

ID: 1113019
Could Valka answer the question so that I can award the 50 points!
0

Accepted Solution

valka earned 50 total points
ID: 1113020
Sorry for delay.
0

## Featured Post

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question