Author Topic: Pixel intensity rounding  (Read 4322 times)

Ben Buse

  • Professor
  • ****
  • Posts: 499
Pixel intensity rounding
« on: May 18, 2015, 01:58:06 AM »
Hi,

I have a puzzle and was wondering if anyone can shed any light on it. Why in calcimage or surfer when I load a grid or prbimage map file are all the numbers integers whereas when I load the map as a image map in surfer each pixcel has decimals.

My question is which is the real number, when does rounding occur?

The x-ray intensities are collected as integers and then converted into cps - so in some cases this would create decimals e.g. 0.3 millisec dwell but if its 0.1 millisec dwell as in the case I was loooking at how do you get decimals

Thanks

Ben
« Last Edit: May 18, 2015, 09:25:52 AM by John Donovan »

Probeman

  • Emeritus
  • *****
  • Posts: 2858
  • Never sleeps...
    • John Donovan
Re: Pixel intensity rounding
« Reply #1 on: May 18, 2015, 09:24:06 AM »
Hi,

I have a puzzle and was wondering if anyone can shed any light on it. Why in calcimage or surfer when I load a grid or prbimage map file are all the numbers integers whereas when I load the map as a image map in surfer each pixcel has decimals.

My question is which is the real number, when does rounding occur?

The x-ray intensities are collected as integers and then converted into cps - so in some cases this would create decimals e.g. 0.3 millisec dwell but if its 0.1 millisec dwell as in the case I was loooking at how do you get decimals

Thanks

Ben

Hi Ben,
Yes, I see it too.   Not sure why.  If I check the Interpolate Pixels checkbox, the image becomes a little more smoothed as expected, but I don't know why there are decimals displayed when the checkbox is unchecked.

Good question for Golden Software I think.  Their forum is here:

http://www.goldensoftware.com/forum/

Please let us know what you find out.
john
« Last Edit: May 18, 2015, 09:25:42 AM by John Donovan »
The only stupid question is the one not asked!

Ben Buse

  • Professor
  • ****
  • Posts: 499
Re: Pixel intensity rounding
« Reply #2 on: May 28, 2015, 01:19:31 AM »
Hi,

Reply to post on surfer forum explains it.

http://www.goldensoftware.com/forum/viewtopic.php?f=1&t=27119&p=47890#p47890

As I currently understand it with interpolate pixcel turned off the color of each pixcel correspondes to the value. But the z value read at the bottom of the screen or plotted on a line profile uses the underlying contouring applied automaticaly to all grid images. This is seen when you create a simply grid



Ben
« Last Edit: May 28, 2015, 01:47:46 AM by Ben Buse »