Active Image or Threading Problem

[David Webster]

All,

I am getting some funny results with the code fragment below. The
IJ.makeOval(...) method works on the current active image. In case 1, when
I leave IJ.log("2: The ... ) commented out, the oval shows up on drawn on
image ip1. I would have thought it would shown up on ip2. In case 2, I un-
comment IJ.log("2: The ... ), then the oval it does show up super-imposed
on ip2. Sometimes, things work the other way around, at least in the first
case. Am I getting some sort of multi-threading problem or does the method
call in the IJ.log(...) somehow change the active image? In any case, how
can I insure that ip2 is the active image.

David Webster


               
ImageProcessor ip1 = new ByteProcessor(100,100);
ImageProcessor ip2 = new ByteProcessor(100,100);
                 
new ImagePlus("ip1", ip1).show();
new ImagePlus("ip2", ip2).show();

//IJ.log("2: The current image is "+WindowManager.getCurrentImage
().getTitle());
               
IJ.makeOval(0,0, 70,70);

[BenTupper]

Hi David,

On Oct 31, 2009, at 2:24 AM, David William Webster wrote:

> All,
>
> I am getting some funny results with the code fragment below. The
> IJ.makeOval(...) method works on the current active image. In case  
> 1, when
> I leave IJ.log("2: The ... ) commented out, the oval shows up on  
> drawn on
> image ip1. I would have thought it would shown up on ip2. In case 2,  
> I un-
> comment IJ.log("2: The ... ), then the oval it does show up super-
> imposed
> on ip2. Sometimes, things work the other way around, at least in the  
> first
> case. Am I getting some sort of multi-threading problem or does the  
> method
> call in the IJ.log(...) somehow change the active image? In any  
> case, how
> can I insure that ip2 is the active image.
>

The following always draws the oval on "ip2" for me.  You might be  
right about the thready thing; using  
WindowManager.setTempCurrentImage() seems to work for this thread.

        ImageProcessor ip1 = new ByteProcessor(100,100);
        ImageProcessor ip2 = new ByteProcessor(100,100);
                               
        ImagePlus imp1 = new ImagePlus("ip1", ip1);
          imp1.show();
        ImagePlus imp2 = new ImagePlus("ip2", ip2);
        imp2.show();

        WindowManager.setTempCurrentImage(imp2);

        IJ.log("2: The current image is  
"+WindowManager.getCurrentImage().getTitle());
        IJ.makeOval(0,0, 70,70);


Cheers,
Ben

> David Webster
>
>
>
> ImageProcessor ip1 = new ByteProcessor(100,100);
> ImageProcessor ip2 = new ByteProcessor(100,100);
>
> new ImagePlus("ip1", ip1).show();
> new ImagePlus("ip2", ip2).show();
>
> //IJ.log("2: The current image is "+WindowManager.getCurrentImage
> ().getTitle());
>
> IJ.makeOval(0,0, 70,70);

Cheers,
Ben

[Wayne Rasband]

You can avoid threading problems like this by creating the ROI and  
adding it to the image using the setRoi() method. And when running  
commands using IJ.run(), it is better to use the version that accepts  
an ImagePlus object as an argument. Here is a JavaScript example that  
inverts the first image and adds an oval ROI to the second:

    ip1 = new ByteProcessor(100,100);
    ip2 = new ByteProcessor(100,100);
                               
    imp1 = new ImagePlus("ip1", ip1);
    imp2 = new ImagePlus("ip2", ip2);

    IJ.run(imp1, "Invert", "");
    roi = new OvalRoi(0,0,70,70)
    imp2.setRoi(roi);

    imp1.show();
    imp2.show();

-wayne

On Oct 31, 2009, at 2:24 AM, David William Webster wrote:

> All,
>
> I am getting some funny results with the code fragment below. The
> IJ.makeOval(...) method works on the current active image. In case  
> 1, when
> I leave IJ.log("2: The ... ) commented out, the oval shows up on  
> drawn on
> image ip1. I would have thought it would shown up on ip2. In case 2,  
> I un-
> comment IJ.log("2: The ... ), then the oval it does show up super-
> imposed
> on ip2. Sometimes, things work the other way around, at least in the  
> first
> case. Am I getting some sort of multi-threading problem or does the  
> method
> call in the IJ.log(...) somehow change the active image? In any  
> case, how
> can I insure that ip2 is the active image.
>
> David Webster
>
>
>
> ImageProcessor ip1 = new ByteProcessor(100,100);
> ImageProcessor ip2 = new ByteProcessor(100,100);
>
> new ImagePlus("ip1", ip1).show();
> new ImagePlus("ip2", ip2).show();
>
> //IJ.log("2: The current image is "+WindowManager.getCurrentImage
> ().getTitle());
>
> IJ.makeOval(0,0, 70,70);