How to use Imageview to display only an image and ROI points

[Guillermo Parada]

Hi, i'm a new user of pyqtgraph and i'm trying to load an image into a imageview widget and then some ROIs, how can i hide the sidebar and the ROI and norm buttons, there is another widget to load an image and ROI points?
Thanks

[Luke Campagnola]

On Mon, May 20, 2013 at 3:02 PM, Guillermo Parada <gin...@gmail.com> wrote:

Hi, i'm a new user of pyqtgraph and i'm trying to load an image into a imageview widget and then some ROIs, how can i hide the sidebar and the ROI and norm buttons, there is another widget to load an image and ROI points?
Thanks

If you don't need any of ImageView's features,  you can just put together a ViewBox with an ImageItem inside it. See pyqtgraph/examples/ROIExamples.py -- the top-left panel in this example has an ImageItem and several ROIs inside a ViewBox. Is that what you're looking for?

Luke

[Guillermo Parada]

Thanks for your quick reply, yes i just found the example, yes is something like that, if can ask you another question, i'm using qt-designer, and in my gui i add the QtgraphicsView widget, how can i make that work with viewbox, because, if i try to add the layout or directly the addviewbox to the widget i receive
error like this : AttributeError: 'GraphicsView' object has no attribute 'addViewBox', how can i set the widget correctly?
Also how can i get the position of a roi point?, using getLocalHandlePositions() i get nothing (using it with imageview)

Thanks.

[Luke Campagnola]

On Mon, May 20, 2013 at 6:01 PM, Guillermo Parada <gin...@gmail.com> wrote:

Thanks for your quick reply, yes i just found the example, yes is something like that, if can ask you another question, i'm using qt-designer, and in my gui i add the QtgraphicsView widget, how can i make that work with viewbox, because, if i try to add the layout or directly the addviewbox to the widget i receive
error like this : AttributeError: 'GraphicsView' object has no attribute 'addViewBox', how can i set the widget correctly?

addViewBox is a method of GraphicsLayoutWidget, not GraphicsView. 

 

Also how can i get the position of a roi point?, using getLocalHandlePositions() i get nothing (using it with imageview)

getLocalHandlePositions gives you the position of handles relative to the ROI itself, so this is probably not much use to you. You can probably use roi.size() and roi.pos() for rectangular ROIs, or roi.getSceneHandlePositions() for other shapes.

Luke

[Guillermo Parada]

Thanks for your reply, was really helpful. There is a more complete documentation that the one on the website?

[Guillermo Parada]

i'm trying to update some label when the ROI change the position, but stateChanged doesn't work, there is another way?

[Guillermo Parada]

What kinf of data return roi.pos(), how can i separate the X and Y into two variables?.

[Luke Campagnola]

On Wed, May 22, 2013 at 5:59 AM, Guillermo Parada <gin...@gmail.com> wrote:

Thanks for your reply, was really helpful. There is a more complete documentation that the one on the website?

No. Unfortunately, the documentation still has a few holes in it. For questions about signals and class members that are not documented, often the best place to look is the source code for each class. As always, I am happy to answer questions here and fill in documentation as needed.

Luke

[Luke Campagnola]

On Wed, May 22, 2013 at 6:44 AM, Guillermo Parada <gin...@gmail.com> wrote:

What kinf of data return roi.pos(), how can i separate the X and Y into two variables?.

This method returns a Point instance, which is a subclass of QPoint: 

http://qt-project.org/doc/qt-4.8/qpoint.html

[Luke Campagnola]

On Wed, May 22, 2013 at 6:02 AM, Guillermo Parada <gin...@gmail.com> wrote:

i'm trying to update some label when the ROI change the position, but stateChanged doesn't work, there is another way?

Here is the documentation I am adding about ROI signals:

    Signals

    ----------------------- ----------------------------------------------------

    sigRegionChangeFinished Emitted when the user stops dragging the ROI (or

                            one of its handles) or if the ROI is changed

                            programatically.

    sigRegionChangeStarted  Emitted when the user starts dragging the ROI (or

                            one of its handles).

    sigRegionChanged        Emitted any time the position of the ROI changes,

                            including while it is being dragged by the user.

    sigHoverEvent           Emitted when the mouse hovers over the ROI.

    sigClicked              Emitted when the user clicks on the ROI

    sigRemoveRequested      Emitted when the user selects 'remove' from the 

                            ROI's context menu (if available).

    ----------------------- ----------------------------------------------------

[Guillermo Parada]

Thanks, is this the right way to capture the signal?
        QtCore.QObject.connect([myroi], QtCore.SIGNAL("sigRegionChangeFinished()"), [my_function])

[Luke Campagnola]

On Wed, May 22, 2013 at 4:42 PM, Guillermo Parada <gin...@gmail.com> wrote:

Thanks, is this the right way to capture the signal?
        QtCore.QObject.connect([myroi], QtCore.SIGNAL("sigRegionChangeFinished()"), [my_function])

I use the "new style" signals--see here:  http://pyqt.sourceforge.net/Docs/PyQt4/new_style_signals_slots.html

So the correct code looks like this:

    myroi.sigRegionChangeFinished.connect(my_function)

[Guillermo Parada]

Works perfectly!! Thanks
There is any ROI related feature to add a visible label to a ROI?
How can i set the movable property to False after i created the ROI?

[Luke Campagnola]

On Thu, May 23, 2013 at 11:54 AM, Guillermo Parada <gin...@gmail.com> wrote:

There is any ROI related feature to add a visible label to a ROI?

There is not, but you can always make a TextItem as a child of the ROI to achieve this effect.

 

How can i set the movable property to False after i created the ROI?

You can set this:

    roi.translatable = False

But note that this only affects dragging the ROI itself; handles will be unaffected.

Luke

[bruno.ba...@gmail.com]

class LabelledROI(ROI):

    """

    Normal ROI with a label attached.

    

    

    ============== =============================================================

    **Arguments**

    label          String for the label 

    \**args        All extra keyword arguments are passed to ROI()

    ============== =============================================================

    

    """

    def __init__(self, *args, label=None, **kwargs):

        ROI.__init__(self, *args, **kwargs)

        if label is not None:

            self.label = QtGui.QGraphicsTextItem(label, self)         

            self.label.setPos(QtCore.QPointF( self.boundingRect().center().x() - (self.label.boundingRect().width()/2),  self.state['size'][1] ))   

        else:

            self.label = None

        

            

    def paint(self, p, opt, widget):

        """ p es un objeto QPainter """

        super().paint(p, opt, widget)

        if self.label is not None:

            self.label.setPos(QtCore.QPointF( self.boundingRect().center().x() - (self.label.boundingRect().width()/2),  self.state['size'][1] ))           

[Tim Williams]

Thanks so much for  posting this! I was just wondering today about how to do this.