Image rotation about the center in python

I guess you must want to understand the image rotation implementation method, so you can refer to the link below for the implementation method: image affine: rotate

Code snippet:

# affine
def affine(img, a, b, c, d, tx, ty):
    H, W, C = _img.shape

    # temporary image
    img = np.zeros((H+2, W+2, C), dtype=np.float32)
    img[1:H+1, 1:W+1] = _img

    # get shape of new image
    H_new = np.round(H).astype(np.int)
    W_new = np.round(W).astype(np.int)
    out = np.zeros((H_new, W_new, C), dtype=np.float32)

    # get position of new image
    x_new = np.tile(np.arange(W_new), (H_new, 1))
    y_new = np.arange(H_new).repeat(W_new).reshape(H_new, -1)

    # get position of original image by affine
    adbc = a * d - b * c
    x = np.round((d * x_new  - b * y_new) / adbc).astype(np.int) - tx + 1
    y = np.round((-c * x_new + a * y_new) / adbc).astype(np.int) - ty + 1

    # adjust center by affine
    dcx = (x.max() + x.min()) // 2 - W // 2
    dcy = (y.max() + y.min()) // 2 - H // 2

    x -= dcx
    y -= dcy

    x = np.clip(x, 0, W + 1)
    y = np.clip(y, 0, H + 1)

    # assign pixcel
    out[y_new, x_new] = img[y, x]
    out = out.astype(np.uint8)

    return out

I didn't answer your question directly, but maybe you can find the answer in the code above.