The following script down samples HR images to LR images for Super-Resolution data preparation. It requires OpenCV and NumPy.
Python Version
import os
import sys
import cv2
import numpy as np
try:
sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
from data.util import imresize_np
except ImportError:
pass
def generate_mod_LR_bic():
# set parameters
up_scale = 4
mod_scale = 4
# set data dir
sourcedir = '/data/datasets/img'
savedir = '/data/datasets/mod'
saveHRpath = os.path.join(savedir, 'HR', 'x' + str(mod_scale))
saveLRpath = os.path.join(savedir, 'LR', 'x' + str(up_scale))
saveBicpath = os.path.join(savedir, 'Bic', 'x' + str(up_scale))
if not os.path.isdir(sourcedir):
print('Error: No source data found')
exit(0)
if not os.path.isdir(savedir):
os.mkdir(savedir)
if not os.path.isdir(os.path.join(savedir, 'HR')):
os.mkdir(os.path.join(savedir, 'HR'))
if not os.path.isdir(os.path.join(savedir, 'LR')):
os.mkdir(os.path.join(savedir, 'LR'))
if not os.path.isdir(os.path.join(savedir, 'Bic')):
os.mkdir(os.path.join(savedir, 'Bic'))
if not os.path.isdir(saveHRpath):
os.mkdir(saveHRpath)
else:
print('It will cover ' + str(saveHRpath))
if not os.path.isdir(saveLRpath):
os.mkdir(saveLRpath)
else:
print('It will cover ' + str(saveLRpath))
if not os.path.isdir(saveBicpath):
os.mkdir(saveBicpath)
else:
print('It will cover ' + str(saveBicpath))
filepaths = [f for f in os.listdir(sourcedir) if f.endswith('.png')]
num_files = len(filepaths)
# prepare data with augementation
for i in range(num_files):
filename = filepaths[i]
print('No.{} -- Processing {}'.format(i, filename))
# read image
image = cv2.imread(os.path.join(sourcedir, filename))
width = int(np.floor(image.shape[1] / mod_scale))
height = int(np.floor(image.shape[0] / mod_scale))
# modcrop
if len(image.shape) == 3:
image_HR = image[0:mod_scale * height, 0:mod_scale * width, :]
else:
image_HR = image[0:mod_scale * height, 0:mod_scale * width]
# LR
image_LR = imresize_np(image_HR, 1 / up_scale, True)
# bic
image_Bic = imresize_np(image_LR, up_scale, True)
cv2.imwrite(os.path.join(saveHRpath, filename), image_HR)
cv2.imwrite(os.path.join(saveLRpath, filename), image_LR)
cv2.imwrite(os.path.join(saveBicpath, filename), image_Bic)
if __name__ == "__main__":
generate_mod_LR_bic()
MATLAB Version
function generate_mod_LR_bic()
%% matlab code to genetate mod images, bicubic-downsampled LR, bicubic_upsampled images.
%% set parameters
% comment the unnecessary line
input_folder = './datasets/input';
% save_mod_folder = '';
save_LR_folder = './datasets/output';
% save_bic_folder = '';
up_scale = 4;
mod_scale = 4;
if exist('save_mod_folder', 'var')
if exist(save_mod_folder, 'dir')
disp(['It will cover ', save_mod_folder]);
else
mkdir(save_mod_folder);
end
end
if exist('save_LR_folder', 'var')
if exist(save_LR_folder, 'dir')
disp(['It will cover ', save_LR_folder]);
else
mkdir(save_LR_folder);
end
end
if exist('save_bic_folder', 'var')
if exist(save_bic_folder, 'dir')
disp(['It will cover ', save_bic_folder]);
else
mkdir(save_bic_folder);
end
end
idx = 0;
filepaths = dir(fullfile(input_folder,'*.*'));
for i = 1 : length(filepaths)
[paths,imname,ext] = fileparts(filepaths(i).name);
if isempty(imname)
disp('Ignore . folder.');
elseif strcmp(imname, '.')
disp('Ignore .. folder.');
else
idx = idx + 1;
str_rlt = sprintf('%d\t%s.\n', idx, imname);
fprintf(str_rlt);
% read image
img = imread(fullfile(input_folder, [imname, ext]));
img = im2double(img);
% modcrop
img = modcrop(img, mod_scale);
if exist('save_mod_folder', 'var')
imwrite(img, fullfile(save_mod_folder, [imname, '.png']));
end
% LR
im_LR = imresize(img, 1/up_scale, 'bicubic');
if exist('save_LR_folder', 'var')
imwrite(im_LR, fullfile(save_LR_folder, [imname, '.png']));
end
% Bicubic
if exist('save_bic_folder', 'var')
im_B = imresize(im_LR, up_scale, 'bicubic');
imwrite(im_B, fullfile(save_bic_folder, [imname, '.png']));
end
end
end
end
%% modcrop
function img = modcrop(img, modulo)
if size(img,3) == 1
sz = size(img);
sz = sz - mod(sz, modulo);
img = img(1:sz(1), 1:sz(2));
else
tmpsz = size(img);
sz = tmpsz(1:2);
sz = sz - mod(sz, modulo);
img = img(1:sz(1), 1:sz(2),:);
end
end