[FIXED] Python - matplotlib - PyQT: plot to QPixmap

Issue

I want to visualise matplotlibs colormaps (similar to http://matplotlib.org/examples/color/colormaps_reference.html) and use it as QPixmaps in PyQt widgets. The idea is to create the plots in matplotlib without actually showing it (or saving it to a file) and convert it to a QPixmap. The solution offered here (Python - matplotlib - PyQT: Copy image to clipboard) doesn't seem to work, maybe because I don't want to show the matplotlib plot.

Solution

I have tried the following and that works:

def testColourMap(cmap):
    sp = SubplotParams(left=0., bottom=0., right=1., top=1.)
    fig = Figure((2.5,.2), subplotpars = sp)
    canvas = FigureCanvas(fig)
    ax = fig.add_subplot(111)
    gradient = np.linspace(0, 1, 256)
    gradient = np.vstack((gradient, gradient))
    ax.imshow(gradient, aspect=10, cmap=cmap)
    ax.set_axis_off()
    canvas.draw()
    size = canvas.size()
    width, height = size.width(), size.height()
    im = QImage(canvas.buffer_rgba(), width, height, QImage.Format_ARGB32)
    return QPixmap(im)

Answered By - Michael