setMinAndMax() fails on currently selected channel of a CompositeImage

[Michael Ellis]

I'm trying to write a plugin that will let me interactively manipulate  
a CompositeImage.
I find setMinAndMax() fails to work on the image processor returned by  
getProcessor(channelIndex)
for the currently selected channel of the CompositeImage.

The plugin below is a minimal piece of code that illustrates my problem.
  It creates an 8 bit 256x256 3 channel CompositeImage filling each  
channel with a ramp.
  By default the LUTS for each channel are:
    channel 1 = red
    channel 2 = green
    channel 3 = blue

I set the min and max values using setMinAndMax(175,200) for each  
channel.
I repeat this three times, selecting channel 1, then 2, then 3. In  
each case the
setMinAndMax(175,200) appears to fail for the currently selected  
channel.

My goal is to create a plugin where I can interactively adjust the  
enabled,
min and max values for every plane in a composite image.

Using setPosition() to select a channel other than the one I want to  
adjust
seems to work around the problem (try setting workAround to true) but  
this
seem inelegant and probably indicative that I am doing something wrong!

   Help!

/
*------------------------------------------------------------------------------------------------------------*/
import ij.CompositeImage;
import ij.IJ;
import ij.ImagePlus;
import ij.plugin.PlugIn;
import ij.process.ImageProcessor;

public class My_Plugin implements PlugIn {

        public My_Plugin() {
        }

        public void run(String arg) {
                for (int channelSelect = 1; channelSelect <= 3; ++channelSelect) {
                        ImagePlus imp = IJ.createImage("Chan select=" + channelSelect, "8-
bit Ramp", 256, 256, 3);
                        CompositeImage ci = new CompositeImage(imp,  
CompositeImage.COMPOSITE);
                        ci.show();

                        ci.setPosition(channelSelect);

                        for (int channelIndex = 1; channelIndex <= 3; ++channelIndex) {
                                boolean workAround = false;
                                if (workAround) {
                                        // Select any channel other than the one we are changing.
                                        ci.setPosition(channelIndex < 3 ? channelIndex + 1 : 1);
                                }
                                final int min = 175, max = 200;
                                ImageProcessor cip = ci.getProcessor(channelIndex);
                                cip.setMinAndMax(min, max);
                                ci.updateAndDraw();
                        }
                }
        }
}

[Rasband, Wayne (NIH/NIMH) [E]]

On May 21, 2010, at 1:07 PM, Michael Ellis wrote:

> I'm trying to write a plugin that will let me interactively manipulate  
> a CompositeImage.
> I find setMinAndMax() fails to work on the image processor returned by  
> getProcessor(channelIndex)
> for the currently selected channel of the CompositeImage.
>
> The plugin below is a minimal piece of code that illustrates my problem.
>  It creates an 8 bit 256x256 3 channel CompositeImage filling each  
> channel with a ramp.
>  By default the LUTS for each channel are:
>   channel 1 = red
>   channel 2 = green
>   channel 3 = blue
>
> I set the min and max values using setMinAndMax(175,200) for each  
> channel.
> I repeat this three times, selecting channel 1, then 2, then 3. In  
> each case the
> setMinAndMax(175,200) appears to fail for the currently selected  
> channel.
>
> My goal is to create a plugin where I can interactively adjust the  
> enabled,
> min and max values for every plane in a composite image.
>
> Using setPosition() to select a channel other than the one I want to  
> adjust
> seems to work around the problem (try setting workAround to true) but  
> this
> seem inelegant and probably indicative that I am doing something wrong!
>
>   Help!

... [show rest of quote]

Try using

    imp.setPosition(channel, imp.getSlice(), imp.getFrame());
    imp.setDisplayRange(min, max);

which is what the "Image>Adjust>Color Balance widget (ij.plugin.frame.ContrastAdjuster.java) uses.

-wayne

>
> /
> *------------------------------------------------------------------------------------------------------------*/
> import ij.CompositeImage;
> import ij.IJ;
> import ij.ImagePlus;
> import ij.plugin.PlugIn;
> import ij.process.ImageProcessor;
>
> public class My_Plugin implements PlugIn {
>
> public My_Plugin() {
> }
>
> public void run(String arg) {
> for (int channelSelect = 1; channelSelect <= 3; ++channelSelect) {
> ImagePlus imp = IJ.createImage("Chan select=" + channelSelect, "8-
> bit Ramp", 256, 256, 3);
> CompositeImage ci = new CompositeImage(imp,  
> CompositeImage.COMPOSITE);
> ci.show();
>
> ci.setPosition(channelSelect);
>
> for (int channelIndex = 1; channelIndex <= 3; ++channelIndex) {
> boolean workAround = false;
> if (workAround) {
> // Select any channel other than the one we are changing.
> ci.setPosition(channelIndex < 3 ? channelIndex + 1 : 1);
> }
> final int min = 175, max = 200;
> ImageProcessor cip = ci.getProcessor(channelIndex);
> cip.setMinAndMax(min, max);
> ci.updateAndDraw();
> }
> }
> }
> }

... [show rest of quote]

[Michael Ellis]

Wayne, thanks. That does the trick.

I don't understand the difference between the two approaches, the code  
for CompositeImage and associated goodies is pretty hairy, but at  
least it is working so I'm a happy bunny!

Many thanks.


On 21 May 2010, at 18:59, Rasband, Wayne (NIH/NIMH) [E] wrote:

> On May 21, 2010, at 1:07 PM, Michael Ellis wrote:
>
>> I'm trying to write a plugin that will let me interactively  
>> manipulate
>> a CompositeImage.
>> I find setMinAndMax() fails to work on the image processor returned  
>> by
>> getProcessor(channelIndex)
>> for the currently selected channel of the CompositeImage.
>>
>> The plugin below is a minimal piece of code that illustrates my  
>> problem.
>> It creates an 8 bit 256x256 3 channel CompositeImage filling each
>> channel with a ramp.
>> By default the LUTS for each channel are:
>>   channel 1 = red
>>   channel 2 = green
>>   channel 3 = blue
>>
>> I set the min and max values using setMinAndMax(175,200) for each
>> channel.
>> I repeat this three times, selecting channel 1, then 2, then 3. In
>> each case the
>> setMinAndMax(175,200) appears to fail for the currently selected
>> channel.
>>
>> My goal is to create a plugin where I can interactively adjust the
>> enabled,
>> min and max values for every plane in a composite image.
>>
>> Using setPosition() to select a channel other than the one I want to
>> adjust
>> seems to work around the problem (try setting workAround to true) but
>> this
>> seem inelegant and probably indicative that I am doing something  
>> wrong!
>>
>>  Help!
>
> Try using
>
>    imp.setPosition(channel, imp.getSlice(), imp.getFrame());
>    imp.setDisplayRange(min, max);
>
> which is what the "Image>Adjust>Color Balance widget  
> (ij.plugin.frame.ContrastAdjuster.java) uses.
>
> -wayne
>

... [show rest of quote]

<snip>

Michael Ellis
Managing Director
Digital Scientific UK Ltd.
http://www.digitalscientific.co.uk
[hidden email]
tel: [phone]
fax: [phone]

Sheraton House
Castle Park
Cambridge
CB3 0AX


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