Image Regression with Custom Head

Part 1 (2019) Advanced (Part 1 v3)
#1

Hi,

I am new to fastai (getting started with the lib), fascinated to see the speed boost, tweaks and productivity it provides in creating models.

Am trying to create a model with custom head from a pre-trained model eg, resnet34 for an Image Regression problem - Price prediction based on Image, but doesn’t know how to achieve it using fastai library.

Looking forward to your help and discussion.

Thank you.

#2

Might be to make the ask clear, am looking forward to know how to setup custom head for a pertained model like resnet in a cleaner way!

#3

HI @LotusGaurdian , what have you been able to do so far? can you draw a picture or some code samples of what you’ve done so far?

Isn’t fine-tuning essentially the same thing? Is the custom head going to be drastically different from the resnet34 model?

#4

Hi Mike,

Thanks for stepping in to guide.

Am very new to fast.ai lib and does’t recognise how to do a standard regression custom head on a pertained body, with concise apis.

Yes, fine-tuning is essentially going to be same, I expect.

The custom head won’t be any different but a standard one.

All I am trying to do is input a image and instead of classifying it, would like to predict it’s expected price in numbers.

Please refer the below image, and sorry for a quick scribble. The challenge is how to do construct via fast.ai lib and begin fine tuning.

Any reference snippets, inputs, reference material would be of great help! Thanks.

ImageRegression
ImageRegression1991×2008 150 KB

1 Like
#5

Thanks for the great diagrams @LotusGaurdian , it becomes much more clear now. Thanks to your post, I looked up image regression and learned a new concept!

Also, it’ beyond my current capabilities to suggest concrete fast.ai snippets etc :sweat_smile: , but just as a general direction, would it make sense to turn this into a multi-class prediction and each prediction represents a price range? So, instead of ‘goldfish’ we take ‘goldfish’ to mean “$120-130” ? To make it finer grained, make the number of categories larger and that’d squeeze the range accordingly?

There was an answer to a similar question previously, not sure if it fits your scenario exactly, but might help in moving things forward a bit?