utils.py

"""
Codes from https://github.com/Newmu/dcgan_code and https://github.com/LeeDoYup/AnoGAN
"""
from __future__ import division
import math
import pprint
import scipy.misc
import numpy as np

pp = pprint.PrettyPrinter()

get_stddev = lambda x, k_h, k_w: 1/math.sqrt(k_w*k_h*x.get_shape()[-1])

def get_image(image_path, input_height, input_width, resize_height=64, resize_width=64, crop=True, grayscale=False):
    image = imread(image_path, grayscale)
    return transform(image, input_height, input_width, resize_height, resize_width, crop)

def save_images(images, size, image_path):
    return imsave(inverse_transform(images), size, image_path)

def imread(path, grayscale = False):
    if (grayscale):
        return scipy.misc.imread(path, flatten = True).astype(np.float)
    else:
        return scipy.misc.imread(path).astype(np.float)

def merge_images(images, size):
    return inverse_transform(images)

def merge(images, size):
    h, w = images.shape[1], images.shape[2]
    if (images.shape[3] in (3,4)):
        c = images.shape[3]
        img = np.zeros((h * size[0], w * size[1], c))
        for idx, image in enumerate(images):
            i = idx % size[1]
            j = idx // size[1]
            img[j * h:j * h + h, i * w:i * w + w, :] = image
        return img
    elif images.shape[3]==1:
        img = np.zeros((h * size[0], w * size[1]))
        for idx, image in enumerate(images):
            i = idx % size[1]
            j = idx // size[1]
            img[j * h:j * h + h, i * w:i * w + w] = image[:,:,0]
        return img
    else:
        raise ValueError('in merge(images,size) images parameter '
                       'must have dimensions: HxW or HxWx3 or HxWx4')

def imsave(images, size, path):
    image = np.squeeze(merge(images, size))
    return scipy.misc.imsave(path, image)

def center_crop(x, crop_h, crop_w, resize_h=64, resize_w=64):
    if crop_w is None:
        crop_w = crop_h
    h, w = x.shape[:2]
    j = int(round((h - crop_h)/2.))
    i = int(round((w - crop_w)/2.))
    return scipy.misc.imresize(x[j:j+crop_h, i:i+crop_w], [resize_h, resize_w])

def transform(image, input_height, input_width, resize_height=64, resize_width=64, crop=True):
    if crop:
        cropped_image = center_crop(
            image, input_height, input_width,
            resize_height, resize_width)
    else:
        cropped_image = scipy.misc.imresize(image, [resize_height, resize_width])
    return np.array(cropped_image)/127.5 - 1.

def inverse_transform(images):
    return (images+1.)/2.

def image_manifold_size(num_images):
    manifold_h = int(np.floor(np.sqrt(num_images)))
    manifold_w = int(np.ceil(np.sqrt(num_images)))
    assert manifold_h * manifold_w == num_images
    return manifold_h, manifold_w