In addition to what Patrick said; you can also call setRect on the image, to place it where you want
image.setRect(pg.Qt.QtCore.QRectF(x0, y0, width, height)) Keep in mind that x0 and y0 represent the top-left corner of the rectangle. On Tue, Jul 12, 2022 at 7:17 PM Patrick <[email protected]> wrote: > Hi Alan, > > The new, accepted way to do this is by applying a QTransform to the > ImageItem. Something like this: > > # Axis labels or limits for the x and y pixels > # If pixel values, they need to be uniform intervals > x = np.array([-1024, 1024]) > y = np.array([-1024, 1024]) > > # Scale in units per pixel > x_scale = (x[-1] - x[0])/(x.shape[0]-1) if x.shape[0] > 1 else 1.0 > y_scale = (y[-1] - y[0])/(y.shape[0]-1) if y.shape[0] > 1 else 1.0 > > # Create QTransform and apply to ImageItem > # Adjust so values are centred on pixels > tr = QtGui.QTransform() > tr.translate(x[0] - x_scale/2, y[0] - y_scale/2) > tr.scale(x_scale, y_scale) > image.setTransform(tr) > > It's just calculating the translation and pixel scale required to map the > pixel coordinates to the desired axis coordinates. > > Patrick > > > > > > On Wednesday, 13 July 2022 at 7:56:44 am UTC+9:30 Alan Wang wrote: > >> Hi all, >> I'm making a graph that displays an image with an ImageItem and >> GraphicsLayoutWidget, but I'd like to label the image with axes on a >> different system of coordinates. When I create a graph, the axes go from 0 >> to 4096 (the size of the image), but I'd like the axes to be labeled from >> -1024 to 1024, essentially remapping the coordinates to a different scale. >> Is there a way to do this? >> >> Thank you >> > -- > 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/85ab2e7c-5418-4946-9110-800983b05387n%40googlegroups.com > <https://groups.google.com/d/msgid/pyqtgraph/85ab2e7c-5418-4946-9110-800983b05387n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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/CA%2BnduTGed5aL%2BBJ9VqLJb-ZFW-sooN8qEiu9QWp9mu4k25kBdg%40mail.gmail.com.
