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How do we draw the result of inference on the original image based on the information of the prediction frame?
First of all, here is just a script for everyone. Specifically, the output from the model needs to go through some post-processing, such as nms to solve it by itself. This script value is for the post-processed output.
The current mainstream target detector takes YOLOX as an example. The output after post-processing is basically output[:, :4]. The coordinates of the bbox represented by the first four will generally convert the center width and height into the coordinates of the upper left corner and lower right corner point. Form, as for output[: , :4] output[:, :5] is the score of whether obj contains the object and the category score respectively, but at present, for example, YOLOv8 has no obj score, it seems that there are only category scores. You can change the script according to the situation. The last dimension is the category index.
def vis(img, boxes, scores, cls_ids, conf=0.5, class_names=None):
'''
img：原始图像
boxes:预测框的位置
scores：分数
cls_ids：类别索引
conf：置信度
class_names：类别列表，应该是列表或者元组
'''
#遍历所有的boxes预测框
for i in range(len(boxes)):
box = boxes[i]
cls_id = int(cls_ids[i])
score = scores[i]
if score < conf:
continue
x0 = int(box[0])
y0 = int(box[1])
x1 = int(box[2])
y1 = int(box[3])
# _COLORS有这个存在可以不同类别画不同颜色的框框
color = (_COLORS[cls_id] * 255).astype(np.uint8).tolist()
text = '{}:{:.1f}%'.format(class_names[cls_id], score * 100)
txt_color = (0, 0, 0) if np.mean(_COLORS[cls_id]) > 0.5 else (0, 255, 0)
#字体
font = cv2.FONT_HERSHEY_SIMPLEX
txt_size = cv2.getTextSize(text, font, 0.4, 1)[0]
cv2.rectangle(img, (x0, y0), (x1, y1), color, 2)
txt_bk_color = (_COLORS[cls_id] * 255 * 0.7).astype(np.uint8).tolist()
cv2.rectangle(
img,
(x0, y0 + 1),
(x0 + txt_size[0] + 1, y0 + int(1.5*txt_size[1])),
txt_bk_color,
-1
)
cv2.putText(img, text, (x0, y0 + txt_size[1]), font, 0.4, txt_color, thickness=1)
return img
_COLORS = np.array(
[
0.000, 0.447, 0.741,
0.850, 0.325, 0.098,
0.929, 0.694, 0.125,
0.494, 0.184, 0.556,
0.466, 0.674, 0.188,
0.301, 0.745, 0.933,
0.635, 0.078, 0.184,
0.300, 0.300, 0.300,
0.600, 0.600, 0.600,
1.000, 0.000, 0.000,
1.000, 0.500, 0.000,
0.749, 0.749, 0.000,
0.000, 1.000, 0.000,
0.000, 0.000, 1.000,
0.667, 0.000, 1.000,
0.333, 0.333, 0.000,
0.333, 0.667, 0.000,
0.333, 1.000, 0.000,
0.667, 0.333, 0.000,
0.667, 0.667, 0.000,
0.667, 1.000, 0.000,
1.000, 0.333, 0.000,
1.000, 0.667, 0.000,
1.000, 1.000, 0.000,
0.000, 0.333, 0.500,
0.000, 0.667, 0.500,
0.000, 1.000, 0.500,
0.333, 0.000, 0.500,
0.333, 0.333, 0.500,
0.333, 0.667, 0.500,
0.333, 1.000, 0.500,
0.667, 0.000, 0.500,
0.667, 0.333, 0.500,
0.667, 0.667, 0.500,
0.667, 1.000, 0.500,
1.000, 0.000, 0.500,
1.000, 0.333, 0.500,
1.000, 0.667, 0.500,
1.000, 1.000, 0.500,
0.000, 0.333, 1.000,
0.000, 0.667, 1.000,
0.000, 1.000, 1.000,
0.333, 0.000, 1.000,
0.333, 0.333, 1.000,
0.333, 0.667, 1.000,
0.333, 1.000, 1.000,
0.667, 0.000, 1.000,
0.667, 0.333, 1.000,
0.667, 0.667, 1.000,
0.667, 1.000, 1.000,
1.000, 0.000, 1.000,
1.000, 0.333, 1.000,
1.000, 0.667, 1.000,
0.333, 0.000, 0.000,
0.500, 0.000, 0.000,
0.667, 0.000, 0.000,
0.833, 0.000, 0.000,
1.000, 0.000, 0.000,
0.000, 0.167, 0.000,
0.000, 0.333, 0.000,
0.000, 0.500, 0.000,
0.000, 0.667, 0.000,
0.000, 0.833, 0.000,
0.000, 1.000, 0.000,
0.000, 0.000, 0.167,
0.000, 0.000, 0.333,
0.000, 0.000, 0.500,
0.000, 0.000, 0.667,
0.000, 0.000, 0.833,
0.000, 0.000, 1.000,
0.000, 0.000, 0.000,
0.143, 0.143, 0.143,
0.286, 0.286, 0.286,
0.429, 0.429, 0.429,
0.571, 0.571, 0.571,
0.714, 0.714, 0.714,
0.857, 0.857, 0.857,
0.000, 0.447, 0.741,
0.314, 0.717, 0.741,
0.50, 0.5, 0
]
).astype(np.float32).reshape(-1, 3)Show results:
