How to maximize FOV¶
By default, when you are using preview
output from ColorCamera, the DepthAI will crop the
frames to get the desired aspect ratio. For example, if you are using Mobilenet-SSD model, you need
300x300
frames. DepthAI will crop 1080P frames to 1080x1080
and then resize them to 300x300
.
This means you will lose some part of the image.
If you would like to maximize the FOV of the image, you can either:
Change the aspect ratio (stretch the image)
Apply letterboxing to the image
Change aspect ratio¶
Use camRgb.setPreviewKeepAspectRatio(False)
. This means the aspect ratio will not be preserved and the image
will be “stretched”. This might be problematic for some off-the-shelf NN models, so model fine-tuning it might be required.
Usage example here.
Letterboxing¶
Letterboxing the frames. This method will decrease
the size of the image and apply “black bars” above and below the image, so the aspect ratio is preserved. You can
achieve this by using ImageManip with manip.setResizeThumbnail(x,y)
(for Mobilenet x=300,y=300
).
The downside of using this method is that your actual image will be smaller, so some features might not be preserved,
which can mean the NN accuracy could decrease.
Usage example here.