How to save images!?

Hello, for the next code, when i run the code i get a subplot as bellow,

But when i save them, they turn into black and white.

Good_RGB=cv2.imread("R_9_1_GSM_5/Good/Original_images/"image_name)
fig, RGB = plt.subplots(1, 3, figsize=(10,10))

for j in range(3):
    RGB[j].imshow(Good_RGB[:,:,j])
    RGB[j].set_title(rgb_list[j], fontsize = 15)

    cv2.imwrite('R_9_1_GSM_5/Good/Red/'+image_name, (Good_RGB[:,:,0]*2))
    cv2.imwrite('R_9_1_GSM_5/Good/Green/'+image_name,(Good_RGB[:,:,1]*2))
    cv2.imwrite('R_9_1_GSM_5/Good/Blue/'+image_name,(Good_RGB[:,:,2]*2))

Answer 1

[DGM]

I have no idea what this code is, but the images are grayscale. When you isolate one color channel, that's all it is. It's a single-channel intensity image. There is no color information.

The images shown are represented as pseudocolor images -- they have a colormap applied to them. In this case, it's probably something similar to parula() or winter(). Use ind2rgb() to apply the selected colormap to the image and create an actual color image.

inpict = imread('peppers.png');
[R G B] = imsplit(inpict);

montage({R G B}) % they're all grayscale

cmap = parula(256);
R = ind2rgb(R,cmap);
G = ind2rgb(G,cmap);
B = ind2rgb(B,cmap);

montage({R G B}) % they're all colormapped using parula()

[Rayan Matlob]

%I rewrite the code in a simple way, i need to save the previeus subplot as shown in the question. thanks

Good_RGB=cv2.imread("R_9_1_GSM_5/Good/Original_images/"image_name)
fig, RGB = plt.subplots(1, 3, figsize=(10,10))
for j in range(3):
    RGB[j].imshow(Good_RGB[:,:,j])
    
    cv2.imwrite('R_9_1_GSM_5/Good/Red/'+image_name, (Good_RGB[:,:,0]*2))
    cv2.imwrite('R_9_1_GSM_5/Good/Green/'+image_name,(Good_RGB[:,:,1]*2))
    cv2.imwrite('R_9_1_GSM_5/Good/Blue/'+image_name,(Good_RGB[:,:,2]*2))

[DGM]

Like I said, I don't know what language that's written in. All I can do is say how it's done in MATLAB.