python 绘制对象检测框及中文信息标注

# 坐标顺序： 上-》左-》下-》右

def draw_bounding_box_on_image(image,

                               ymin,

                               xmin,

                               ymax,

                               xmax,

                               color='red',

                               thickness=4,

                               display_str_list=(),

                               use_normalized_coordinates=True):

    """

    Args:

      image: a cv2 object.

      ymin: ymin of bounding box.

      xmin: xmin of bounding box.

      ymax: ymax of bounding box.

      xmax: xmax of bounding box.

      color: color to draw bounding box. Default is red.

      thickness: line thickness. Default value is 4.

      display_str_list: list of strings to display in box

                        (each to be shown on its own line).

      use_normalized_coordinates: If True (default), treat coordinates

        ymin, xmin, ymax, xmax as relative to the image.  Otherwise treat

        coordinates as absolute.

    """

    image = Image.fromarray(cv2.cvtColor(image, cv2.COLOR_BGR2RGB))

    draw = ImageDraw.Draw(image)

    # 获取图像的宽度与高度

    im_width, im_height = image.size

    if use_normalized_coordinates:

        (left, right, top, bottom) = (xmin * im_width, xmax * im_width,

                                    ymin * im_height, ymax * im_height)

    else:

        (left, right, top, bottom) = (xmin, xmax, ymin, ymax)

    # 绘制Box框

    draw.line([(left, top), (left, bottom), (right, bottom),

               (right, top), (left, top)], width=thickness, fill=color)

    # 加载字体

    try:

        font = ImageFont.truetype("font/simsun.ttc", 24, encoding="utf-8")

    except IOError:

        font = ImageFont.load_default()

    # 计算显示文字的宽度集合 、高度集合

    display_str_width = [font.getsize(ds)[0] for ds in display_str_list]

    display_str_height = [font.getsize(ds)[1] for ds in display_str_list]

    # 计算显示文字的总宽度

    total_display_str_width = sum(display_str_width) + max(display_str_width) * 1.1

    # 计算显示文字的最大高度

    total_display_str_height = max(display_str_height)

    if top > total_display_str_height:

        text_bottom = top

    else:

        text_bottom = bottom + total_display_str_height

    # 计算文字背景框最右侧可到达的像素位置

    if right < (left + total_display_str_width):

        text_right = right

    else:

        text_right = left + total_display_str_width

    # 绘制文字背景框

    draw.rectangle(

            [(left, text_bottom), (text_right, text_bottom - total_display_str_height)],

            fill=color)    

    # 计算文字背景框可容纳的文字，若超出部分不显示，改为补充“..”

    for index in range(len(display_str_list[::1])):

        current_right = (left + (max(display_str_width)) + sum(display_str_width[0:index + 1]))

        if current_right < text_right:

            print(current_right)

            display_str = display_str_list[:index + 1]

        else:

            display_str = display_str_list[0:index - 1] + '...'

            break  

    # 绘制文字

    draw.text(

            (left + max(display_str_width) / 2, text_bottom - total_display_str_height),

            display_str,

            fill='black',

            font=font)

    return cv2.cvtColor(np.asarray(image), cv2.COLOR_RGB2BGR)
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python 绘制对象检测框及中文信息标注

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