Index out of bounds exception

[MiguelFRomeroR]

Hi, thanks for sharing the code. Your solution has been really helpful for me!

However, I found a small issue. You can replicate it by changing line 20:
self.FOV = [0.45, 0.45]
to
self.FOV = [0.3, 0.3]

and line 113:
center_point = np.array([0.5, .5])
to
center_point = np.array([0.5, .9])

It triggers the exception at line 76, in _bilinear_interpolation.

IndexError: index 8389700 is out of bounds for size 8388608

To solve it, I added the following, after line 64:

x2 = np.minimum(x2, self.frame_width-1)
y2 = np.minimum(y2, self.frame_height-1)

I think the error occurs because for the interpolation, you take pixel i and pixel i+1, and in some specific cases, pixel i is already the last pixel (either in width or height).

Hope it helps.

[gogozhu]

Hi, thanks for your solution. I also encountered this problem.

However, when I tried your solution, I found another issue.

As we know, the first pixel and the last pixel on the latitude of an equirectangular image are continuous, which means the pixel i+1 should be 0 rather than width when the pixel i is the last pixel. Therefor, I think the correct solution should be the following.

First, you can change line 62
x2 = np.add(x0, np.ones(uf.shape).astype(int)) # coords of pixel to top right
to
_x2 = np.add(x0, np.ones(uf.shape).astype(int)) # coords of pixel to top right

Then add the following after line 64:

x2 = np.mod(_x2, self.frame_width)  
y2 = np.minimum(y2, self.frame_height-1)

Finally, in order to correct the bilinear interpolation, the x2 in line 80 and 81 should be changed to _x2.

wa = np.multiply(_x2 - uf, y2 - vf)
wb = np.multiply(_x2 - uf, vf - y0)

Hope it helps.

[kwea123]

If you install opencv-python, there is a more concise way, add the following lines after
spericalCoord = self._calcSphericaltoGnomonic(convertedScreenCoord)

sphericalCoord = sphericalCoord.reshape(self.height, self.width, 2).astype(np.float32) % 1
out = cv2.remap(frame, 
                        sphericalCoord[..., 0]*self.frame_width, 
                        sphericalCoord[..., 1]*self.frame_height, 
                        interpolation=cv2.INTER_LINEAR,
                        borderMode=cv2.BORDER_WRAP)
return out

then you don't need the handcrafted _bilinear_interpolation anymore. It produces the same result.

[KevinHwangKR]

Hey, could you tell me how you were able to run this program please?