Python cv2.COLOR_BGRA2RGBA Examples

def cv2_imshow(a):
  """A replacement for cv2.imshow() for use in Jupyter notebooks.

  Args:
    a : np.ndarray. shape (N, M) or (N, M, 1) is an NxM grayscale image. shape
      (N, M, 3) is an NxM BGR color image. shape (N, M, 4) is an NxM BGRA color
      image.
  """
  a = a.clip(0, 255).astype('uint8')
  # cv2 stores colors as BGR; convert to RGB
  if a.ndim == 3:
    if a.shape[2] == 4:
      a = cv2.cvtColor(a, cv2.COLOR_BGRA2RGBA)
    else:
      a = cv2.cvtColor(a, cv2.COLOR_BGR2RGB)
  display.display(PIL.Image.fromarray(a)) 

def main():

    jpg_inputs = find_inputs(JPGPATH, types=('.jpg',), prefix=PREFIX)
    tif_inputs = find_inputs(TIFPATH, types=('.tif',), prefix=PREFIX)

    jpg_stats = []
    for f in jpg_inputs:
        img = cv2.imread(f[1])
        mean, std = cv2.meanStdDev(img)
        jpg_stats.append(np.array([mean[::-1] / 255, std[::-1] / 255]))
    jpg_vals = np.mean(jpg_stats, axis=0)
    print(jpg_vals)

    tif_stats = []
    for f in tif_inputs:
        img = cv2.imread(f[1], -1)
        img = cv2.cvtColor(img, cv2.COLOR_BGRA2RGBA)
        mean, std = cv2.meanStdDev(img)
        tif_stats.append(np.array([mean, std]))
    tif_vals = np.mean(tif_stats, axis=0)
    print(tif_vals) 

def copy_figure_to_clipboard(fig):
    """
    References:
        https://stackoverflow.com/questions/17676373/python-matplotlib-pyqt-copy-image-to-clipboard
    """
    print('Copying figure %d to the clipboard' % fig.number)
    import matplotlib as mpl
    app = mpl.backends.backend_qt5.qApp
    QtGui = mpl.backends.backend_qt5.QtGui
    im_bgra = render_figure_to_image(fig, transparent=True)
    im_rgba = cv2.cvtColor(im_bgra, cv2.COLOR_BGRA2RGBA)
    im = im_rgba
    QImage = QtGui.QImage
    qim = QImage(im.data, im.shape[1], im.shape[0], im.strides[0], QImage.Format_RGBA8888)
    clipboard = app.clipboard()
    clipboard.setImage(qim)

    # size = fig.canvas.size()
    # width, height = size.width(), size.height()
    # qim = QtGui.QImage(fig.canvas.buffer_rgba(), width, height, QtGui.QImage.Format_ARGB32)

    # QtWidgets = mpl.backends.backend_qt5.QtWidgets
    # pixmap = QtWidgets.QWidget.grab(fig.canvas)
    # clipboard.setPixmap(pixmap) 

def bgra2rgba(img):
    a = alpha(img)
    rgba = cv2.cvtColor(img, cv2.COLOR_BGRA2RGBA)
    if a is not None:
        rgba[:, :, 3] = a
    return rgba


## RGBA to BGRA. 

def bgra2rgba(img):
    a = alpha(img)
    rgba = cv2.cvtColor(img, cv2.COLOR_BGRA2RGBA)
    if a is not None:
        rgba[:, :, 3] = a
    return rgba


## RGBA to BGRA. 

def save(path, img): #TODO: multimethod..?
    if len(img.shape) == 3:
        n_channels = img.shape[-1]
        if n_channels == 4:   # bgra -> rgba
            rgb_img = cv2.cvtColor(img, cv2.COLOR_BGRA2RGBA)
        elif n_channels == 3: # bgr -> rgb
            rgb_img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
    elif len(img.shape) == 2: # bw = bw
        rgb_img = img

    imageio.imwrite(path, rgb_img) 

def convert_channel_from_bgra(img, num_channels):
        if num_channels in [0, 1]:
            img = cv2.cvtColor(img, cv2.COLOR_BGRA2GRAY)
            if num_channels == 1:
                img = img[..., np.newaxis]

            return img

        elif num_channels == 3:  # BGRA => RGB
            return cv2.cvtColor(img, cv2.COLOR_BGRA2RGB)

        elif num_channels in [-1, 4]:  # BGRA => RGBA
            return cv2.cvtColor(img, cv2.COLOR_BGRA2RGBA, dst=img)

        raise ValueError("num_channels must be [-1, 0, 1, 3, 4]") 

def on_show_image (self, wnd_name, img):
        pass
        # # cv2 stores colors as BGR; convert to RGB
        # if img.ndim == 3:
        #     if img.shape[2] == 4:
        #         img = cv2.cvtColor(img, cv2.COLOR_BGRA2RGBA)
        #     else:
        #         img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
        # img = PIL.Image.fromarray(img)
        # plt.imshow(img)
        # plt.show() 

def overlay(src_image, overlay_image, pos_x, pos_y):
    # オーバレイ画像のサイズを取得
    ol_height, ol_width = overlay_image.shape[:2]

    # OpenCVの画像データをPILに変換
    # BGRAからRGBAへ変換
    src_image_RGBA = cv2.cvtColor(src_image, cv2.COLOR_BGR2RGB)
    overlay_image_RGBA = cv2.cvtColor(overlay_image, cv2.COLOR_BGRA2RGBA)

    #　PILに変換
    src_image_PIL=Image.fromarray(src_image_RGBA)
    overlay_image_PIL=Image.fromarray(overlay_image_RGBA)

    # 合成のため、RGBAモードに変更
    src_image_PIL = src_image_PIL.convert('RGBA')
    overlay_image_PIL = overlay_image_PIL.convert('RGBA')

    # 同じ大きさの透過キャンパスを用意
    tmp = Image.new('RGBA', src_image_PIL.size, (255, 255,255, 0))
    # 用意したキャンパスに上書き
    tmp.paste(overlay_image_PIL, (pos_x, pos_y), overlay_image_PIL)
    # オリジナルとキャンパスを合成して保存
    result = Image.alpha_composite(src_image_PIL, tmp)

    return  cv2.cvtColor(np.asarray(result), cv2.COLOR_RGBA2BGRA)

# 画像周辺のパディングを削除 

def generator():
    global ename, esex, enation, eyear, emon, eday, eaddr, eidn, eorg, elife, ebgvar
    name = ename.get()
    sex = esex.get()
    nation = enation.get()
    year = eyear.get()
    mon = emon.get()
    day = eday.get()
    org = eorg.get()
    life = elife.get()
    addr = eaddr.get()
    idn = eidn.get()

    fname = askopenfilename(initialdir=os.getcwd(), title=u'选择头像')
    # print fname
    im = PImage.open(os.path.join(base_dir, 'empty.png'))
    avatar = PImage.open(fname)  # 500x670

    name_font = ImageFont.truetype(os.path.join(base_dir, 'hei.ttf'), 72)
    other_font = ImageFont.truetype(os.path.join(base_dir, 'hei.ttf'), 60)
    bdate_font = ImageFont.truetype(os.path.join(base_dir, 'fzhei.ttf'), 60)
    id_font = ImageFont.truetype(os.path.join(base_dir, 'ocrb10bt.ttf'), 72)

    draw = ImageDraw.Draw(im)
    draw.text((630, 690), name, fill=(0, 0, 0), font=name_font)
    draw.text((630, 840), sex, fill=(0, 0, 0), font=other_font)
    draw.text((1030, 840), nation, fill=(0, 0, 0), font=other_font)
    draw.text((630, 980), year, fill=(0, 0, 0), font=bdate_font)
    draw.text((950, 980), mon, fill=(0, 0, 0), font=bdate_font)
    draw.text((1150, 980), day, fill=(0, 0, 0), font=bdate_font)
    start = 0
    loc = 1120
    while start + 11 < len(addr):
        draw.text((630, loc), addr[start:start + 11], fill=(0, 0, 0), font=other_font)
        start += 11
        loc += 100
    draw.text((630, loc), addr[start:], fill=(0, 0, 0), font=other_font)
    draw.text((950, 1475), idn, fill=(0, 0, 0), font=id_font)
    draw.text((1050, 2750), org, fill=(0, 0, 0), font=other_font)
    draw.text((1050, 2895), life, fill=(0, 0, 0), font=other_font)
    
    if ebgvar.get():
        avatar = cv2.cvtColor(np.asarray(avatar), cv2.COLOR_RGBA2BGRA)
        im = cv2.cvtColor(np.asarray(im), cv2.COLOR_RGBA2BGRA)
        im = changeBackground(avatar, im, (500, 670), (690, 1500))
        im = PImage.fromarray(cv2.cvtColor(im, cv2.COLOR_BGRA2RGBA))
    else:
        avatar = avatar.resize((500, 670))
        avatar = avatar.convert('RGBA')
        im.paste(avatar, (1500, 690), mask=avatar)
        #im = paste(avatar, im, (500, 670), (690, 1500))
        

    im.save('color.png')
    im.convert('L').save('bw.png')

    showinfo(u'成功', u'文件已生成到目录下,黑白bw.png和彩色color.png')