I want to display an RGBColor bitmap as an image
I have several functions that fill the bitmap.
also at some point I will add an alpha channel.
I saw similar questions but none of them worked for me.
display an rgb matrix image in python
I have an RGBColor class defined as
class RGBColor:
bytes = np.zeros(3, dtype=np.ubyte)
# RGBColor.__new__
def __new__(cls, *args, **kwargs):
return super().__new__(cls)
# RGBColor.__init__
def __init__(self, r: int, g: int, b: int) -> None:
self.bytes[0] = r
self.bytes[1] = g
self.bytes[2] = b
and a Bitmap defined as
class Bitmap:
# Point.__new__
def __new__(cls, *args, **kwargs):
return super().__new__(cls)
# Point.__init__
def __init__(self, rows: int, cols: int, backColor: RGBColor) -> None:
self.bits = np.empty( (rows,cols), dtype=RGBColor)
for r in range(rows):
for c in range(cols):
self.bits[r][c] = backColor
and my attempt at displaying this is
import numpy as np
import matplotlib.pyplot as plt
def show(self, bitmap: Bitmap):
plt.imshow(bitmap.bits)
plt.show()
The error I get is
File
“C:ProgramDataAnaconda3libsite-packagesmatplotlibimage.py”, line
706, in set_data
raise TypeError(“Image data of dtype {} cannot be converted to “TypeError: Image data of dtype object cannot be converted to float
1
You created an array of RGBColor objects. imshow can only handle int or float arrays, so you’d need a function to convert your object array to an int or float array. Here is an example of such a function (can certainly be optimized):
def to_numpy(self):
return np.array([b.bytes.tolist() for b in self.bits.flat], dtype=np.ubyte).reshape(self.bits.shape + (3,))
Then you can call it like
bitmap = Bitmap(3, 2, RGBColor(100, 50, 200))
plt.imshow(bitmap.to_numpy())