Thanks for reply Luc! Any thoughs on whether using QGraphicsTextItem would be preferable to modifying the paint() of ImageItem?
Kuba On Wed, Dec 20, 2017 at 7:01 AM, Luke Campagnola <[email protected]> wrote: > In the past I have used QGraphicsTextItem with a monospace font for > displaying grids of characters. > That should yield good performance, depending on the size of your image. > > On Fri, Dec 15, 2017 at 7:33 AM, Kuba Raczkowski <[email protected] > > wrote: > >> Ok, well, managed to do it based on https://stackoverflow.com/q >> uestions/4763992/finding-out-what-portion-of-a-qgraphicsitem >> -is-visible-in-a-qgraphicsview# >> >> FYI, this gives a visible rectangle inside an imageitem, in its >> coordinates: >> >> view = self.getViewBox().getViewWidget() >> portRect = view.viewport().rect() >> sceneRect = view.mapToScene(portRect).boundingRect() >> itemRect = self.mapRectFromScene(sceneRect) >> isec = itemRect.intersected(self.boundingRect()) >> >> >> Kuba >> >> On Friday, December 15, 2017 at 4:10:09 PM UTC+1, Kuba Raczkowski wrote: >>> >>> Hi, >>> >>> I'm trying to annotate the ImageItem's pixels by a textual value on top >>> of every pixel. >>> Got it working by extending the paint() and adding necessary drawText() >>> calls, however, the performance is (obviously?) terrible. >>> >>> This is only meant to be useful when zooming in deeply - that I can >>> treshold by figuring out pixelSize() of ImageItem. >>> >>> However, all labels seem to be painted even if only a few pixels are >>> visible in the view. >>> Any idea how to figure out the pixels (or a rectangle) that are actually >>> visible in the view? I'm getting lost in all the coordinate mappings :/ >>> >>> >>> Best regards, >>> Kuba >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "pyqtgraph" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit https://groups.google.com/d/ms >> gid/pyqtgraph/8a620fae-e972-4761-89da-25bf2490d095%40googlegroups.com >> <https://groups.google.com/d/msgid/pyqtgraph/8a620fae-e972-4761-89da-25bf2490d095%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> >> For more options, visit https://groups.google.com/d/optout. >> > > -- > You received this message because you are subscribed to a topic in the > Google Groups "pyqtgraph" group. > To unsubscribe from this topic, visit https://groups.google.com/d/ > topic/pyqtgraph/vR8t4JAlhVA/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web visit https://groups.google.com/d/ > msgid/pyqtgraph/CACZXET9QCrUQEnNWE_c5nksYBug2OQ_vcdKUnr8t% > 3D7aVQsr7SA%40mail.gmail.com > <https://groups.google.com/d/msgid/pyqtgraph/CACZXET9QCrUQEnNWE_c5nksYBug2OQ_vcdKUnr8t%3D7aVQsr7SA%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "pyqtgraph" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/pyqtgraph/CAFFUSEOBZS_vFBF%2BRE7ijdUvhoQ_z8PnD22dTnFHxHZfobu0NQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
