dataloader中getitem函数问题

[li784]

if len(box) != 0: box[:, [0, 2]] = box[:, [0, 2]] / self.input_shape[1] box[:, [1, 3]] = box[:, [1, 3]] / self.input_shape[0]

box[:, 2:4] = box[:, 2:4] - box[:, 0:2]
box[:, 0:2] = box[:, 0:2] + box[:, 2:4] / 2

最后两行为啥要这样做呢。这不是对一个box的处理吗，为啥还hw减去yx和xy+wh / 2 box[:, 2:4] = box[:, 2:4] - box[:, 0:2] box[:, 0:2] = box[:, 0:2] + box[:, 2:4] / 2

[taqaddum]

这里box的四列分别是：左上角坐标(x1, y1)，右下角坐标(x2, y2)，这两行的目的是将左上右下坐标转换成中心点(x, y)+宽高(w, h)的形式，因为网络的输出张量是(x, y, w, h, conf, classes)。

# 图像的坐标原点在左上角
box[:, [2:4]] = box[:, 2:4] - box[:, 0:2]  # 求宽高，w=x2-x1，h=y2-y1
box[:, 0:2] = box[:, 0:2] + box[:, 2:4] / 2  # 求中心点，x=x1+w/2, y=y1+h/2

[li784]

感谢感谢，仔细看了下xml的格式是xmin ymin xmax ymax的，我之前一直以为是xywh

[bubbliiiing]

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