Support RGB virtual stacks

[hinerm]

When I try to open AVI images right now, they get to the point of converting to an ImagePlus and then I get the following exception:

    [Method] protected void org.scijava.ui.DefaultUIService.onEvent(org.scijava.display.event.DisplayCreatedEvent)
java.lang.IllegalArgumentException: RGB stacks not supported
    at ij.CompositeImage.<init>(CompositeImage.java:54)
    at net.imagej.legacy.translate.AbstractImagePlusCreator.makeImagePlus(AbstractImagePlusCreator.java:175)
    at net.imagej.legacy.translate.AbstractImagePlusCreator.makeImagePlus(AbstractImagePlusCreator.java:96)
    at net.imagej.legacy.translate.ColorImagePlusCreator.cellImgCase(ColorImagePlusCreator.java:152)
    at net.imagej.legacy.translate.ColorImagePlusCreator.createLegacyImage(ColorImagePlusCreator.java:104)
    at net.imagej.legacy.translate.DefaultImageTranslator.createLegacyImage(DefaultImageTranslator.java:124)
    at net.imagej.legacy.translate.DefaultImageTranslator.createLegacyImage(DefaultImageTranslator.java:110)
    at net.imagej.legacy.LegacyImageMap.registerDisplay(LegacyImageMap.java:179)
    at net.imagej.legacy.display.LegacyImageDisplayViewer.view(LegacyImageDisplayViewer.java:99)
    at net.imagej.legacy.ui.LegacyUI$1.run(LegacyUI.java:167)
    at org.scijava.thread.DefaultThreadService.invoke(DefaultThreadService.java:91)
    at net.imagej.legacy.ui.LegacyUI.show(LegacyUI.java:163)
    at org.scijava.ui.DefaultUIService.onEvent(DefaultUIService.java:378)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.scijava.event.DefaultEventService$ProxySubscriber.onEvent(DefaultEventService.java:278)
    at org.scijava.event.DefaultEventService$ProxySubscriber.onEvent(DefaultEventService.java:252)
    at org.bushe.swing.event.ThreadSafeEventService.publish(ThreadSafeEventService.java:971)
    at org.scijava.event.DefaultEventBus.access$101(DefaultEventBus.java:56)
    at org.scijava.event.DefaultEventBus$1.run(DefaultEventBus.java:197)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:302)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:694)
    at java.awt.EventQueue$3.run(EventQueue.java:692)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

So I'm pretty sure we can't open any .avi files until scifio/scifio#191 is resolved, and still we should make this work for virtual datasets.

[dscho]

Actually, it should be pretty easy to split the RGB images on imagej-legacy's side, no? Let's discuss this tomorrow in person.

[hinerm]

note that other datasets are broken by this, too.. e.g. the dice.gif sample, which is an indexed time series and thus ends up being opened as an RGB stack, which fails.

Anyway yes let's discuss today @dscho ... i'd like to resolve this quickly.

[hinerm]

argh.. this was the wrong fix.. working on it now. we just want to be smarter about when wrapping in a composite image.

[dscho]

I fear we'll have to add a Auto-convert grayscale .gif/.jpg images when loading with SCIFIO checkbox (needs help with the exact label, of course), defaulting to true to abide by the Law of the Least Surprise...

[hinerm]

OK I think the color support is now correct and should clear up some confusion about RGB and composite images.. also, 3+ dim GIF and AVI should work again.

Fixed as of 5f77360