MaskRCNN 的 segm IoU 指标从何而来 = 0？答案

【问题标题】：Whence MaskRCNN's segm IoU metrics = 0?MaskRCNN 的 segm IoU 指标从何而来 = 0？
【发布时间】：2021-12-12 02:44:45
【问题描述】：

在我的多类实例分割自定义数据集上训练 MaskRCNN 时，输入格式为：

image   -)  shape: torch.Size([3, 850, 600]),   dtype: torch.float32, min: tensor(0.0431),               max: tensor(0.9137)
boxes   -)  shape: torch.Size([4, 4]),          dtype: torch.float32, min: tensor(47.),                  max: tensor(807.)
masks   -)  shape: torch.Size([850, 600, 600]), dtype: torch.uint8,   min: tensor(0, dtype=torch.uint8), max: tensor(1, dtype=torch.uint8)
areas   -)  shape: torch.Size([4]),             dtype: torch.float32, min: tensor(1479.),                max: tensor(8014.)
labels  -)  shape: torch.Size([4]),             dtype: torch.int64,   min: tensor(1),                    max: tensor(1)
iscrowd -)  shape: torch.Size([4]),             dtype: torch.int64,   min: tensor(0),                    max: tensor(0)

我始终如一地获得所有细分IoU指标，如下所示：

DONE (t=0.03s).
IoU metric: bbox
 Average Precision  (AP) @[ IoU=0.50:0.95 | area=   all | maxDets=100 ] = 0.004
 Average Precision  (AP) @[ IoU=0.50      | area=   all | maxDets=100 ] = 0.010
 Average Precision  (AP) @[ IoU=0.75      | area=   all | maxDets=100 ] = 0.000
 Average Precision  (AP) @[ IoU=0.50:0.95 | area= small | maxDets=100 ] = 0.000
 Average Precision  (AP) @[ IoU=0.50:0.95 | area=medium | maxDets=100 ] = 0.000
 Average Precision  (AP) @[ IoU=0.50:0.95 | area= large | maxDets=100 ] = 0.004
 Average Recall     (AR) @[ IoU=0.50:0.95 | area=   all | maxDets=  1 ] = 0.000
 Average Recall     (AR) @[ IoU=0.50:0.95 | area=   all | maxDets= 10 ] = 0.000
 Average Recall     (AR) @[ IoU=0.50:0.95 | area=   all | maxDets=100 ] = 0.000
 Average Recall     (AR) @[ IoU=0.50:0.95 | area= small | maxDets=100 ] = 0.000
 Average Recall     (AR) @[ IoU=0.50:0.95 | area=medium | maxDets=100 ] = 0.000
 Average Recall     (AR) @[ IoU=0.50:0.95 | area= large | maxDets=100 ] = 0.001
IoU metric: segm
 Average Precision  (AP) @[ IoU=0.50:0.95 | area=   all | maxDets=100 ] = 0.000
 Average Precision  (AP) @[ IoU=0.50      | area=   all | maxDets=100 ] = 0.000
 Average Precision  (AP) @[ IoU=0.75      | area=   all | maxDets=100 ] = 0.000
 Average Precision  (AP) @[ IoU=0.50:0.95 | area= small | maxDets=100 ] = 0.000
 Average Precision  (AP) @[ IoU=0.50:0.95 | area=medium | maxDets=100 ] = 0.000
 Average Precision  (AP) @[ IoU=0.50:0.95 | area= large | maxDets=100 ] = 0.000
 Average Recall     (AR) @[ IoU=0.50:0.95 | area=   all | maxDets=  1 ] = 0.000
 Average Recall     (AR) @[ IoU=0.50:0.95 | area=   all | maxDets= 10 ] = 0.000
 Average Recall     (AR) @[ IoU=0.50:0.95 | area=   all | maxDets=100 ] = 0.000
 Average Recall     (AR) @[ IoU=0.50:0.95 | area= small | maxDets=100 ] = 0.000
 Average Recall     (AR) @[ IoU=0.50:0.95 | area=medium | maxDets=100 ] = 0.000
 Average Recall     (AR) @[ IoU=0.50:0.95 | area= large | maxDets=100 ] = 0.000

我该如何思考、调试和解决这个问题？

【问题讨论】：

标签： pytorch torch

【解决方案1】：

由于您的输入图像大小为 (850, 600) (H, W)，并且考虑到对于此给定图像，您有 4 个对象，而不是带有 (600, 600) 掩码的 850 个对象。你的面具张量应该有维度（对象数，850、600），因此你的输入应该是：

image   -)  shape: torch.Size([3, 850, 600]),   dtype: torch.float32, min: tensor(0.0431),               max: tensor(0.9137)
boxes   -)  shape: torch.Size([4, 4]),          dtype: torch.float32, min: tensor(47.),                  max: tensor(807.)
masks   -)  shape: torch.Size([4, 850, 600]), dtype: torch.uint8,   min: tensor(0, dtype=torch.uint8), max: tensor(1, dtype=torch.uint8)
areas   -)  shape: torch.Size([4]),             dtype: torch.float32, min: tensor(1479.),                max: tensor(8014.)
labels  -)  shape: torch.Size([4]),             dtype: torch.int64,   min: tensor(1),                    max: tensor(1)
iscrowd -)  shape: torch.Size([4]),             dtype: torch.int64,   min: tensor(0),                    max: tensor(0)

如何解决因为您正在尝试解决实例分割问题，所以请确保您的每个 (850, 600) 掩码都堆叠起来，以便产生 (number of mask, 850, 600) 形状的张量。

【讨论】：