Author Archives: Robin Dong

The uneasy way to implement SSDLite by myself

SSDLite is a variant of Single Shot Multi-box Detection. It uses MobileNetV2 instead of VGG as backbone. Thus it can make detection extremely fast. I was trying to implement SSDLite from the code base of ssd.pytorch. Although it’s not a easy work, I finally learn a lot from the entire… Read more »

A tip about Terraform

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Terraform is a interesting (in my opinion) tool to implement Infrastructure-as-Code. When I first used it to write production script at yesterday, I met a error report:

After a while of searching on Google, I got the cause: it can’t find my AWS credential in my computer. Actually I… Read more »

The weird comparison behaviours of Python string

A part of my code didn’t work well, as below:

It will not print out anything totally. So I directly printed out the actually value of mapping[‘colour’]:

Why ‘Red’ is not ‘Red’? After changed the judgement from ‘is’ to ‘==’, the result became correct. The key is that… Read more »

Tips about Numpy and PyTorch

1. Type convertion in Numpy Here is my code:

Guess what? The type of variable ‘c’ is ‘float64’! Seems Numpy automatically considers a empty array of Python as ‘float64’ type. So the correct code should be:

This time, the type of ‘c’ is ‘int64’ 2. Convert a tensor… Read more »

Using Single Shot Detection to detect birds (Episode three)

In the previous article, I reached mAP 0.740 for VOC2007 test. After one month, I found out that the key to boost the performance of object detction is not only based on cutting edge model, but also depends on sophisticated augmentation methodology. Therefore I manually checked every image generated by… Read more »

Some tips for opencv-python

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Type conversion Using opencv-python to add object-detection rectangle for the image:

The result looks like this But in a more complicated program, I processed a image from float32 type. Therefore the code looks like:

But this time, the rectangle disappeared. The reason is opencv-python use numpy array for… Read more »