Keras model.predict() not predicting classes for some images

Question

I have trained a ResNet50 using Keras for classication. For testing, I used the ImageDataGenerator flow_from_directory() method to pass input to the model. Here's the code for that:

testdata_generator = keras.preprocessing.image.ImageDataGenerator(
    preprocessing_function=tf.keras.applications.resnet.preprocess_input
)

testgen = testdata_generator.flow_from_directory(
    './test',
    shuffle=False,
    target_size=(224,224),
    color_mode='rgb',
    batch_size=32,
    class_mode=None
)

Found 18223 images belonging to 1 classes.

However when I test the model on the test images, it doesn't predict for a few images.

pred = model.predict(
    testgen,
    batch_size=32,
    steps=testgen.n//testgen.batch_size
)
print(len(pred))

18208

Anyone help?

Answer 1

You should try removing steps=testgen.n//testgen.batch_size, since calculating the steps results in a different number of samples, when you have a remainder by dividing samples // batch_size.