yapic-io 0.1.4

io data handling module for various image sources as interface for pixel classification tools

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# yapic_io

yapic_io provides flexible data binding to image collections of arbitrary size.

Its aim is to provide a convenient image data interface for training of fully convolutional neural networks, as well as automatic handling of prediction data output for a trained classifier.

yapic_io is designed as a convenient image data input/output interface for libraries such as Theano or TensorFlow.

Following problems occuring with training/classification are handeled by yapic_io:

• Images of different sizes in z,x, and y can be applied to the same convolutional network. This is implemented by sliding windows. The size these windows correspond to the size of the convolutional network’s input layer.

• Due to lazy data loading, images can be extremely large.

• Image dimensions can be up to 4D (multchannel z-stack), as e.g. required for bioimages.

• Data augmentation for classifier training in built in.

• Made for sparsly labelled datasets: Training data is only (randomly) picked from regions where labels are present.

• Usually, input layers of CNNs are larger than output layers. Thus, pixels located at image edges are normally not classified. With yapic_io also edge pixels are classified. This is achieved by mirroring pixel data in edge regions. As a result, output classification images have identical dimensions as source images and can be overlayed easily.

## Example

Classifier training:

` >>> from yapic_io import TiffConnector, Dataset, TrainingBatch >>> >>> #define data locations >>> pixel_image_dir = 'yapic_io/test_data/tiffconnector_1/im/*.tif' >>> label_image_dir = 'yapic_io/test_data/tiffconnector_1/labels/*.tif' >>> savepath = 'yapic_io/test_data/tmp/' >>> >>> >>> tpl_size = (1,5,4) # size of network output layer in zxy >>> padding = (0,2,2) # padding of network input layer in zxy, in respect to output layer >>> >>> c = TiffConnector(pixel_image_dir, label_image_dir, savepath=savepath) >>> train_data = TrainingBatch(Dataset(c), tpl_size, padding_zxy=padding) >>> >>> counter=0 >>> for mini in train_data: ... weights = mini.weights ... #shape of weights is (6,3,1,5,4) : batchsize 6 , 3 label-classes, 1 z, 5 x, 4 y ... ... pixels = mini.pixels() ... # shape of pixels is (6,3,1,9,8) : 3 channels, 1 z, 9 x, 4 y (more xy due to padding) ... ... #here: apply training on mini.pixels and mini.weights (use theano, tensorflow...) ... my_train_function(pixels, weights) ... ... counter += 1 ... if counter > 10: #m is infinite ... break ` Prediction: ` >>> from yapic_io import TiffConnector, Dataset, PredictionBatch >>> >>> #mock classification function >>> def classify(pixels, value): ... return np.ones(pixels.shape) * value >>> >>> #define data loacations >>> pixel_image_dir = 'yapic_io/test_data/tiffconnector_1/im/*.tif' >>> label_image_dir = 'yapic_io/test_data/tiffconnector_1/labels/*.tif' >>> savepath = 'yapic_io/test_data/tmp/' >>> >>> tpl_size = (1,5,4) # size of network output layer in zxy >>> padding = (0,2,2) # padding of network input layer in zxy, in respect to output layer >>> >>> c = TiffConnector(pixel_image_dir, label_image_dir, savepath=savepath) >>> prediction_data = PredictionBatch(Dataset(c)) >>> len(prediction_data) #give the total number of templates that cover the whole bound tifffiles 510 >>> >>> #classify the whole bound dataset >>> counter = 0 #needed for mock data >>> for item in prediction_data: ... pixels_for_classifier = item.pixels() #input for classifier ... mock_classifier_result = classify(pixels, counter) #classifier output ... ... #pass classifier results for each class to data source ... item.put_probmap_data(mock_classifier_result) ... ... counter += 1 #counter for generation of mockdata >>> `

## Buils API docs

` cd docs sphinx-apidoc -o source ../yapic_io make html `

Developed by the CRFS (Core Research Facilities) of the DZNE (German Center for Neurodegenerative Diseases).