🚀 go-pugleaf

In article <fred.722416637@dip3> fred@dip3.ee.uct.ac.za (Fred Hoare) writes:
>I (and the other people in my lab) have a requirement to be able
>to display 16 bit greyscale images on a Sun workstation. We have
>several pieces of software that display images, but they all convert
>the images to 8 bit first. What we require is a display routine that
>would allow a person to choose what intensity range in the image was
>displayed on the screen, at any time. I presume this would be done by 
>changing the way the lookup table gets mapped to the data.

The way that I attack it is to either just truncate the lower 8 bits
or to scale the data so that the maximum value is mapped into 255 and
the minimum value is mapped into 0.  The can either be done by table
lookup or through some direct scaling.

I'm not sure what is meant by "allow a person to choose what intensity
range was displayed on the screen..."  I suppose that you could use a
sliding eight bit window that could be used as a mask to map into the
color table but without a lot of fiddling the images are going to look
awfully strange.

							spl
-- 
Steve Lamont, SciViGuy -- (619) 534-7968 -- spl@szechuan.ucsd.edu
UCSD Microscopy and Imaging Resource/UCSD Med School/La Jolla, CA 92093-0608
"Far out, man"
            - President George Bush, heard in a stump speech on NPR

In article <fred.722416637@dip3> fred@dip3.ee.uct.ac.za (Fred Hoare) writes:
>I (and the other people in my lab) have a requirement to be able
>to display 16 bit greyscale images on a Sun workstation. We have
>several pieces of software that display images, but they all convert
>the images to 8 bit first. What we require is a display routine that
>would allow a person to choose what intensity range in the image was
>displayed on the screen, at any time. I presume this would be done by 
>changing the way the lookup table gets mapped to the data.
>
>Does anyone know of software under X11 that is capable of doing this?
>
>Thanks in advance for any replies.
>Fred
>--
>Frederick Hoare                email: fred@dip1.ee.uct.ac.za
>Image Processing Laboratory
>Department of Electrical and Electronic Engineering
>University of Cape Town,  South Africa

Me too.  Except I'd like to such software running on a PC.  I do
some programming, please let me know any hints about programming
LUTs to display >8 bits images in addition to available software.

Thanks in advance.                

James Zheng

spl@ivem.ucsd.edu (Steve Lamont) writes:

>In article <fred.722416637@dip3> fred@dip3.ee.uct.ac.za (Fred Hoare) writes:
>>I (and the other people in my lab) have a requirement to be able
>>to display 16 bit greyscale images on a Sun workstation. We have
>>several pieces of software that display images, but they all convert
>>the images to 8 bit first. What we require is a display routine that
>>would allow a person to choose what intensity range in the image was
>>displayed on the screen, at any time. I presume this would be done by 
>>changing the way the lookup table gets mapped to the data.

>The way that I attack it is to either just truncate the lower 8 bits
>or to scale the data so that the maximum value is mapped into 255 and
>the minimum value is mapped into 0.  The can either be done by table
>lookup or through some direct scaling.

>I'm not sure what is meant by "allow a person to choose what intensity
>range was displayed on the screen..."  I suppose that you could use a
>sliding eight bit window that could be used as a mask to map into the
>color table but without a lot of fiddling the images are going to look
>awfully strange.

That is exactly what I meant. The images we work with consist of both
medical and satelite images and it is often very helpful to be able to
look at a specific range of intensities in the image. It is a lot easier
to do this using a lookup table modification than to actually truncate
the image to the range required, then scale this to 8 bits before display.

Fred
--
Frederick Hoare                email: fred@dip1.ee.uct.ac.za
Image Processing Laboratory
Department of Electrical and Electronic Engineering
University of Cape Town,  South Africa

In article <1992Nov22.205215.5677@news.columbia.edu>,
qiang@cubmol.bio.columbia.edu (Qiang Zheng) writes:
> In article <fred.722416637@dip3> fred@dip3.ee.uct.ac.za (Fred Hoare) writes:
>>I (and the other people in my lab) have a requirement to be able
>>to display 16 bit greyscale images on a Sun workstation. We have
>>several pieces of software that display images, but they all convert
>>the images to 8 bit first. What we require is a display routine that
>>would allow a person to choose what intensity range in the image was
>>displayed on the screen, at any time. I presume this would be done by 
>>changing the way the lookup table gets mapped to the data.
>>
>>Does anyone know of software under X11 that is capable of doing this?
 
Not offhand.  I know exactly what you want though.  I currently
use PV-Wave to do most of my image processing and display.  It 
allows easy display of a desired data window but you have to
re-enter each new max and min value when you want to look
at a new range.   Ideally, one would have a track-ball user interface
in which one axis controls the location of the sliding window
and the other controls the width.

> Me too.  Except I'd like to such software running on a PC.  I do
> some programming, please let me know any hints about programming
> LUTs to display >8 bits images in addition to available software.

I don't believe normal PC's are capable of even 8-bit gray-scale
display because the RGB D/A converters are 6 bits for VGA cards.
Photometrics LTD. has some software that allows the data to be 
easily windowed for display with a fairly decent user interface.
The only catch is that you need to have a certain type of VGA
card (ET4000 chipset I believe) and the image file format is
nonstandard (although they give you the specs - it's basically
16 bits/pixel with a header).   The software is meant to work with 
their camera hardware, but it should function ok without it.  You might
give them a call to see if they offer it without the hardware.
Their phone number is: 602-889-9933 and the name of the software
is IMAGE200.  
 
--
+---------------------------------------------------------------------+
|Dick Wallingford      | Internet: dickw@iastate.edu                  |
|Center for NDE        | Packet  : wd0anb@n0an.ia.usa.na              |
|Iowa State University | I'm not a musician, but I play one in a band | 
+---------------------------------------------------------------------+

In article <1992Nov23.085417@IASTATE.EDU> dickw@IASTATE.EDU (Richard Wallingford) writes:
>In article <1992Nov22.205215.5677@news.columbia.edu>,
>qiang@cubmol.bio.columbia.edu (Qiang Zheng) writes:
>> In article <fred.722416637@dip3> fred@dip3.ee.uct.ac.za (Fred Hoare) writes:
>>>I (and the other people in my lab) have a requirement to be able
>>>to display 16 bit greyscale images on a Sun workstation. We have
>>>several pieces of software that display images, but they all convert
>>>the images to 8 bit first. What we require is a display routine that
>>>would allow a person to choose what intensity range in the image was
>>>displayed on the screen, at any time. I presume this would be done by 
>>>changing the way the lookup table gets mapped to the data.
>>>
>>>Does anyone know of software under X11 that is capable of doing this?
> 
>Not offhand.  I know exactly what you want though.  I currently
>use PV-Wave to do most of my image processing and display.  It 
>allows easy display of a desired data window but you have to
>re-enter each new max and min value when you want to look
>at a new range.   Ideally, one would have a track-ball user interface
>in which one axis controls the location of the sliding window
>and the other controls the width.
>
>> Me too.  Except I'd like to such software running on a PC.  I do
>> some programming, please let me know any hints about programming
>> LUTs to display >8 bits images in addition to available software.
>
>I don't believe normal PC's are capable of even 8-bit gray-scale
>display because the RGB D/A converters are 6 bits for VGA cards.
>Photometrics LTD. has some software that allows the data to be 
>easily windowed for display with a fairly decent user interface.
>The only catch is that you need to have a certain type of VGA
>card (ET4000 chipset I believe) and the image file format is
>nonstandard (although they give you the specs - it's basically
>16 bits/pixel with a header).   The software is meant to work with 
>their camera hardware, but it should function ok without it.  You might
>give them a call to see if they offer it without the hardware.
>Their phone number is: 602-889-9933 and the name of the software
>is IMAGE200.  
> 
>--
>+---------------------------------------------------------------------+
>|Dick Wallingford      | Internet: dickw@iastate.edu                  |
>|Center for NDE        | Packet  : wd0anb@n0an.ia.usa.na              |
>|Iowa State University | I'm not a musician, but I play one in a band | 
>+---------------------------------------------------------------------+

You ought to check into MIRA, from Axiom Research, Inc., Tucson, AZ.
602-791-2864.

MIRA processes and displays 8 and 16 bit integer images and 32 bit float 
images and allows real time contrast/brightness control with a mouse.
True, SVGA only allows 64 shades of gray, but it does allow up to 256
different colors on the screen.  Dropping to 64 grays is not a big loss.
386 and 486 systems are VERY capable at image processing if they have decent
software.  A 486/50 can give a Sparc II a run for it's money.