Setting part of image data as NaN breaks the image

[Luka Drmic]

Hello i have a little problem that i cant find a solution to.

I have an ImageItem to which i add some data i plot it.

central_item = pg.GraphicsLayout()
main_subplot = central_item.addPlot()
img = pg.ImageItem()
img.setImage(self.plt_data)
main_subplot.addItem(img)

After that i change that data, and some parts of data become NaN. (I have tried np.nan and float("NaN"), neither works)

This breaks my imageitem and the whole image is displayed as black. Any ideas how ti fix this

Additional info:

 - example data before correction:

[[ 1.26721e-09  1.19301e-09  1.11133e-09 ... -7.82147e-10 -8.43276e-10
  -8.80460e-10]
 [ 1.21326e-09  1.14925e-09  1.05997e-09 ... -8.08065e-10 -8.45355e-10
  -9.01877e-10]
 [ 1.15840e-09  1.06533e-09  9.91163e-10 ... -8.41492e-10 -8.84370e-10
  -9.44690e-10]
 ...
 [ 3.08664e-09  2.73720e-09  2.46942e-09 ... -4.24728e-10 -4.37422e-10
  -4.55941e-10]
 [ 3.15188e-09  2.82395e-09  2.54162e-09 ... -4.35917e-10 -4.45014e-10
  -4.64306e-10]
 [ 3.30943e-09  2.97556e-09  2.65902e-09 ... -4.49749e-10 -4.56709e-10
  -4.71022e-10]]

 - example data after correction

[[            nan  1.19301021e-09  1.11133022e-09 ... -7.82147116e-10
  -8.43276076e-10             nan]
 [            nan  1.14925018e-09  1.05997023e-09 ... -8.08065073e-10
  -8.45355116e-10             nan]
 [            nan  1.06533024e-09  9.91163178e-10 ... -8.41492088e-10
  -8.84370129e-10             nan]
 ...
 [            nan  2.73720232e-09  2.46942160e-09 ... -4.24728013e-10
  -4.37422020e-10             nan]
 [            nan  2.82395225e-09  2.54162174e-09 ... -4.35917010e-10
  -4.45014021e-10             nan]
 [            nan  2.97556241e-09  2.65902204e-09 ... -4.49749008e-10
  -4.56709016e-10             nan]]

 - image before correction

 - image after correction

Desired result would be like in the image below which is produced by setting values to 0 instead of NaN, which is something i dont want to do because data at those points is not actually 0, its unknown.