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PaddlePaddle / PaddleDetection

Object Detection toolkit based on PaddlePaddle. It supports object detection, instance segmentation, multiple object tracking and real-time multi-person keypoint detection.
Apache License 2.0
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where dose the std and mean value come from? #1504

Closed dongyu-HIT closed 3 years ago

dongyu-HIT commented 3 years ago

where dose the std and mean value come from? std [0.229,0.224,0.225] mean [0.485, 0.456, 0.406] This confuses me

qingqing01 commented 3 years ago

@dongyu-HIT

In the data agumentation, std and mean is used to normalize image, y = (x - mean)/std, x is the input image, y is the normalized image.

Usually, if use the pretrained ImageNet classification models, the mean and std are same with them in classification task. Usually come from ImageNet.

songyuc commented 3 years ago

Hi, @qingqing01 , if I want to train the model from scratch, what mean and std should I set?