Fix rotation direction in visualize_gaussians due to inverted Y-axis

[MathisDupont]

Hello,
First I want to thank you for the code provided!

When visualizing gaussians with the function visualize_gaussians in utils/image_utils.py, it seems the angle calculation needs to be inverted.

Since the Y-axis is inverted for image plotting (plt.ylim(img_h, 0)), the rotation direction is flipped. The angle should likely be: -rot[gid, 0] * 180 / np.pi instead of: rot[gid, 0] * 180 / np.pi

Relevant lines:

image-gs/utils/image_utils.py

Lines 189 to 192 in 7f74702

	for gid in range(len(xy)):
	ellipse = Ellipse(xy=(x[gid], y[gid]), width=scale[gid, 0], height=scale[gid, 1],
	angle=rot[gid, 0]*180/np.pi, alpha=alpha, ec=None, fc=curr_feat[gid], lw=None)
	ax.add_patch(ellipse)

Hope it helps,
Best regards