suppress matplotlib warning for OD render

lib/imaging.py

@@ -8,6 +8,7 @@ import numpy.linalg as la
 import lmfit
 import pathlib
 import toml
+import warnings
 import PIL.Image
 import lib.plotdefs as pd
 
@@ -109,6 +110,7 @@ class ImagingData:
         for label, array in self.arrays.items():
             if printflag: print(f"[imaging] render {label}")
             if label == "od":
+                warnings.filterwarnings("ignore")
                 H, W = array.shape
                 (pd.Plotter()
                     .imshow(array,
@@ -122,6 +124,7 @@ class ImagingData:
                     .savefig(T.joinpath(label + ".png"))
                     .close()
                 )
+                warnings.resetwarnings()
             else:
                 PIL.Image.fromarray(array).save(T.joinpath(label + ".png"))
         #if printflag: print("  Done.")