Augmentation Issues

[jesusbft]

I notticed the augmentation option didn't help to improve the results.

I inspected some augmented images and I noticed some options distort the image making them useless:

I'm still figure out which will be the best option for my dataset, but it's only possible change the class DefaultAugmenter(). Maybe would be interesting create a way to set these parameters dynamically.

Thank you

[jesusbft]

More details attached:

class DefaultAugmenter():

Option: ElasticTransform(alpha=64, sigma=25, p=1.0),

Option: Affine(translate_px=(0, 5), rotate=(-3, 3), shear=(-5, 5), p=1.0)

I disabled both of them which are causing distortions above what I wanted.

Thank you

[jesusbft]

Update:

I could not find a way to use any rotation, scale or shear. All these options lose information in the borders. In the affine function has a parameter to fit_output, but it causes issues in the height size.

The translate_px option is not util here and also loses information.

The alpha parameter in the ElasticTransform couldn't be higher than 10. After that, it causes large deformation.

These are the settings that I use now:

        self._transforms = Compose([
                                    ToFloat(),
                                    PixelDropout(p=0.2),
                                    OneOf([
                                        MotionBlur(p=0.2),
                                        MedianBlur(blur_limit=3, p=0.1),
                                        Blur(blur_limit=3, p=0.1),
                                    ], p=0.2),
                                    OneOf([
                                        OpticalDistortion(p=0.3),
                                        ElasticTransform(alpha=7, sigma=25, p=0.1),
                                    ], p=0.2),
                                   ], p=0.5)

[jesusbft]

SafeRotate is a good option:

SafeRotate(limit=(-3,3), border_mode=cv2.BORDER_CONSTANT, p=0.2)