How to get prediction and confidence of that prediction using resnet - machine-learning

Question

I have a binary classifier which predicts whether the image is positive or negative. I am using model.predict for getting the detections. So basically what I want is the class index and the confidence value with which it belongs to that class. I am able to get the detections and able to show it on the image, but for background images also it is showing some false predictions so I would like to remove those by setting a threshold for the confidence. For information about the training file and testing file I have asked a question on StackOverflow, please refer the link "Resnet is showing wrong predictions even without any object"
My Resnet code:
# import the necessary packages
from keras.layers.normalization import BatchNormalization
from keras.layers.convolutional import Conv2D
from keras.layers.convolutional import AveragePooling2D
from keras.layers.convolutional import MaxPooling2D
from keras.layers.convolutional import ZeroPadding2D
from keras.layers.core import Activation
from keras.layers.core import Dense
from keras.layers import Flatten
from keras.layers import Input
from keras.models import Model
from keras.layers import add
from keras.regularizers import l2
from keras import backend as K
class ResNet:
#staticmethod
def residual_module(data, K, stride, chanDim, red=False,
reg=0.0001, bnEps=2e-5, bnMom=0.9):
# the shortcut branch of the ResNet module should be
# initialize as the input (identity) data
shortcut = data
# the first block of the ResNet module are the 1x1 CONVs
bn1 = BatchNormalization(axis=chanDim, epsilon=bnEps,
momentum=bnMom)(data)
act1 = Activation("relu")(bn1)
conv1 = Conv2D(int(K * 0.25), (1, 1), use_bias=False,
kernel_regularizer=l2(reg))(act1)
# the second block of the ResNet module are the 3x3 CONVs
bn2 = BatchNormalization(axis=chanDim, epsilon=bnEps,
momentum=bnMom)(conv1)
act2 = Activation("relu")(bn2)
conv2 = Conv2D(int(K * 0.25), (3, 3), strides=stride,
padding="same", use_bias=False,
kernel_regularizer=l2(reg))(act2)
# the third block of the ResNet module is another set of 1x1
# CONVs
bn3 = BatchNormalization(axis=chanDim, epsilon=bnEps,
momentum=bnMom)(conv2)
act3 = Activation("relu")(bn3)
conv3 = Conv2D(K, (1, 1), use_bias=False,
kernel_regularizer=l2(reg))(act3)
# if we are to reduce the spatial size, apply a CONV layer to
# the shortcut
if red:
shortcut = Conv2D(K, (1, 1), strides=stride,
use_bias=False, kernel_regularizer=l2(reg))(act1)
# add together the shortcut and the final CONV
x = add([conv3, shortcut])
# return the addition as the output of the ResNet module
return x
#staticmethod
def build(width, height, depth, classes, stages, filters,
reg=0.0001, bnEps=2e-5, bnMom=0.9):
# initialize the input shape to be "channels last" and the
# channels dimension itself
inputShape = (height, width, depth)
chanDim = -1
# if we are using "channels first", update the input shape
# and channels dimension
if K.image_data_format() == "channels_first":
inputShape = (depth, height, width)
chanDim = 1
# set the input and apply BN
inputs = Input(shape=inputShape)
x = BatchNormalization(axis=chanDim, epsilon=bnEps,
momentum=bnMom)(inputs)
# apply CONV => BN => ACT => POOL to reduce spatial size
x = Conv2D(filters[0], (5, 5), use_bias=False,
padding="same", kernel_regularizer=l2(reg))(x)
x = BatchNormalization(axis=chanDim, epsilon=bnEps,
momentum=bnMom)(x)
x = Activation("relu")(x)
x = ZeroPadding2D((1, 1))(x)
x = MaxPooling2D((3, 3), strides=(2, 2))(x)
# loop over the number of stages
for i in range(0, len(stages)):
# initialize the stride, then apply a residual module
# used to reduce the spatial size of the input volume
stride = (1, 1) if i == 0 else (2, 2)
x = ResNet.residual_module(x, filters[i + 1], stride,
chanDim, red=True, bnEps=bnEps, bnMom=bnMom)
# loop over the number of layers in the stage
for j in range(0, stages[i] - 1):
# apply a ResNet module
x = ResNet.residual_module(x, filters[i + 1],
(1, 1), chanDim, bnEps=bnEps, bnMom=bnMom)
# apply BN => ACT => POOL
x = BatchNormalization(axis=chanDim, epsilon=bnEps,
momentum=bnMom)(x)
x = Activation("relu")(x)
x = AveragePooling2D((8, 8))(x)
# softmax classifier
x = Flatten()(x)
x = Dense(classes, kernel_regularizer=l2(reg))(x)
x = Activation("softmax")(x)
# create the model
model = Model(inputs, x, name="resnet")
# return the constructed network architecture
return model
Any kind of suggestion to get rid of my this problem would be really helpful