title: Linear interpolation in Keras
body: <p>How can I add a linear interpolation layer in Keras? </p>
  
  <p>I have hourglass network ("channel_first"), and at some point in decoder part I have to do a linear interpolation from size (32,128,152) to (32,128,256) after my relu layer. </p>
  
  <p>I tried conv2DTranspose and Upsampling2D none of which allow fractional upsampling rate. Reshape and Imageresize also did not work. (my input is not an image it's a raw data matrix size 64*2462)</p>