Disable image downsampling when n=1

pyqtgraph/functions.py

@@ -1222,6 +1222,8 @@ def downsample(data, n, axis=0, xvals='subsample'):
             data = downsample(data, n[i], axis[i])
         return data
     
+    if n <= 1:
+        return data
     nPts = int(data.shape[axis] / n)
     s = list(data.shape)
     s[axis] = nPts

pyqtgraph/graphicsItems/ImageItem.py

@@ -9,6 +9,8 @@ from .GraphicsObject import GraphicsObject
 from ..Point import Point
 
 __all__ = ['ImageItem']
+
+
 class ImageItem(GraphicsObject):
     """
     **Bases:** :class:`GraphicsObject <pyqtgraph.GraphicsObject>`