Is KotlinDL planning to add a normalize `transform...

# kotlindl

[Alexandre Brown]

Is KotlinDL planning to add a normalize transformTensor op that could be done after the rescale for instance ?

I can contribute but want to know if you already did it for 0.4 first.

[Julia Beliaeva]

Hi, yes, the 0.4 release will add a normalize preprocessor. See https://github.com/Kotlin/kotlindl/issues/204 and the example usage in https://github.com/Kotlin/kotlindl/blob/master/examples/src/main/kotlin/examples/dataset/NormalizeExample.kt

[Alexandre Brown]

Awesome, we'll upgrade to use 0.4 alpha then! Is the format BGR for the mean and std arrays? so index 0 = Blue ?

[Julia Beliaeva]

The format of the mean and std arrays should be the same as in the input image. If image is BGR, then the arrays should be in BGR.

[Alexandre Brown]

Perfect thank you and is the image type from buffered image type the right place to check if the image is BGR? In my case I have an RGB image but when I do getImage and check the type it's BGR so I suppose Java/kotlin opens images in BGR by default?

ImageConverter.toBufferedImage(File(imagePath).inputStream()).type

[Julia Beliaeva]

Hmm, no, as far as I know, it's not supposed to change the format.

[Julia Beliaeva]

is the image type from buffered image type the right place to check if the image is BGR?

Yes.
Btw, KotlinDL now also has a convert image preprocessor to convert image format (currently, between rgb, bgr and grayscale).

[Alexandre Brown]

That's awesome, I'll make use of the convert preprocessor, Thanks a lot @Julia Beliaeva !!

[Julia Beliaeva]

Sorry, it seems that I was wrong. It looks like jpeg images read by ImageIO always have BGR order. It's controlled by this constant com.sun.imageio.plugins.jpeg.JPEG#bOffsRGB which is set to { 2, 1, 0 }.

[Alexandre Brown]

Hey just a feedback, last week I used the alpha (0.4.3) and added normalize and convert ops to our existing kotlinDL preprocessing and it worked amazingly well.
Thanks again for your reply.

@Julia Beliaeva @zaleslaw Keep up the good work on KotlinDL we're in love with the lib so far.