How many sub-volume do we have to make?

Certainly, I was training a model using 25 sub-volumes from one 3D image. The model learned well with that data; however, overfitting persists because I only used one 3D image. If I create all sub-volumes for 484 images, I will have 12,100 sub-volumes, and it takes too long to train the model. So, my question is, how many sub-volumes should we create for each image to achieve good results in data validation? Specifically, I want to avoid overfitting. Has anyone tried this approach before?

1 Like

How about trying total 300 images and dividing 240 training dataset(80%) and 60 validation dataset(20%)

anything lower than that can also work but will question model’s accuracy.

A total of 100 images would be must (dividing into 80-20) subset.

Regards
DP

Is creating 25 sub-volumes for each image a good choice for this dataset, or can I try making only 10 sub-volumes for each image? Please answer based on your experience. Thank you, sir.

1 Like

Experience would come with trial and error. I cannot give a definite answer on an incomplete understanding of your data and model algorithm planning.

Sub-volume can be decided based on your input shape, like in the assignment the 3D image had (240, 240, 155) which in sub-volume was converted to generate (160, 160, 16)

I hope you have gone through the data processing using patches section properly from the assignment.

No one can confirm sub-volume without knowing the data in detail. Although as I can see you are going to use less number images you could probably go ahead with 10 sub-volumes, cannot confirm.

Wait for your choice of expertise advise :slight_smile:

Regards
DP

You are right, the number of sub-volumes cannot be confirmed as it also depends on the model algorithm. I just don’t have much time for trial and error because the deadline for my paper is running out. Thank you, sir, for the advice.

1 Like


here is the error sir, @Deepti_Prasad

1 Like

Hello @Elvaret_M168DSX1546

your error is coming with the line mentioned for X[i, :, :, :]

Can I know the reason behind transposing both x data and y data here??

Based on this webpage (3D Data-Augmentation Using tf.data and Volumentations-3D Library | by Fakrul Islam Tushar | Medium) and this repository (volumentations/example.py at master · ashawkey/volumentations · GitHub, the Volumentations library for augmentation requires the input shape to be in the form [imgs: [D, H, W, C], where the depth or batch dimension should be the first]. To match this shape, I transpose the dimensions (because my X dimension is [num_channel, dim_x, dim_y, dim_z]), and after the augmentation, I revert the shape back.

1 Like

Hello Elvaret,

the reason I think this issue is arising because you are mask for the y data after the transpose of x data and y data.

Can I know reason behind using mask for the y data??