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waifu2x/lib/data_augmentation.lua
2018-10-03 18:30:22 +09:00

279 lines
7.9 KiB
Lua

require 'pl'
require 'cunn'
local iproc = require 'iproc'
local gm = {}
gm.Image = require 'graphicsmagick.Image'
local data_augmentation = {}
local function pcacov(x)
local mean = torch.mean(x, 1)
local xm = x - torch.ger(torch.ones(x:size(1)), mean:squeeze())
local c = torch.mm(xm:t(), xm)
c:div(x:size(1) - 1)
local ce, cv = torch.symeig(c, 'V')
return ce, cv
end
function random_rect_size(rect_min, rect_max)
local r = torch.Tensor(2):uniform():cmul(torch.Tensor({rect_max - rect_min, rect_max - rect_min})):int()
local rect_h = r[1] + rect_min
local rect_w = r[2] + rect_min
return rect_h, rect_w
end
function random_rect(height, width, rect_h, rect_w)
local r = torch.Tensor(2):uniform():cmul(torch.Tensor({height - 1 - rect_h, width-1 - rect_w})):int()
local rect_y1 = r[1] + 1
local rect_x1 = r[2] + 1
local rect_x2 = rect_x1 + rect_w
local rect_y2 = rect_y1 + rect_h
return {x1 = rect_x1, y1 = rect_y1, x2 = rect_x2, y2 = rect_y2}
end
function data_augmentation.erase(src, p, n, rect_min, rect_max)
if torch.uniform() < p then
local src, conversion = iproc.byte2float(src)
src = src:contiguous():clone()
local ch = src:size(1)
local height = src:size(2)
local width = src:size(3)
for i = 1, n do
local rect_h, rect_w = random_rect_size(rect_min, rect_max)
local rect1 = random_rect(height, width, rect_h, rect_w)
local rect2 = random_rect(height, width, rect_h, rect_w)
dest_rect = src:sub(1, ch, rect1.y1, rect1.y2, rect1.x1, rect1.x2)
src_rect = src:sub(1, ch, rect2.y1, rect2.y2, rect2.x1, rect2.x2)
dest_rect:copy(src_rect:clone())
end
if conversion then
src = iproc.float2byte(src)
end
return src
else
return src
end
end
function data_augmentation.color_noise(src, p, factor)
factor = factor or 0.1
if torch.uniform() < p then
local src, conversion = iproc.byte2float(src)
local src_t = src:reshape(src:size(1), src:nElement() / src:size(1)):t():contiguous()
local ce, cv = pcacov(src_t)
local color_scale = torch.Tensor(3):uniform(1 / (1 + factor), 1 + factor)
pca_space = torch.mm(src_t, cv):t():contiguous()
for i = 1, 3 do
pca_space[i]:mul(color_scale[i])
end
local dest = torch.mm(pca_space:t(), cv:t()):t():contiguous():resizeAs(src)
dest:clamp(0.0, 1.0)
if conversion then
dest = iproc.float2byte(dest)
end
return dest
else
return src
end
end
function data_augmentation.overlay(src, p)
if torch.uniform() < p then
local r = torch.uniform()
local src, conversion = iproc.byte2float(src)
src = src:contiguous()
local flip = data_augmentation.flip(src)
flip:mul(r):add(src * (1.0 - r))
if conversion then
flip = iproc.float2byte(flip)
end
return flip
else
return src
end
end
function data_augmentation.unsharp_mask(src, p)
if torch.uniform() < p then
local radius = 0 -- auto
local sigma = torch.uniform(0.5, 1.5)
local amount = torch.uniform(0.1, 0.9)
local threshold = torch.uniform(0.0, 0.05)
local unsharp = gm.Image(src, "RGB", "DHW"):
unsharpMask(radius, sigma, amount, threshold):
toTensor("float", "RGB", "DHW")
if src:type() == "torch.ByteTensor" then
return iproc.float2byte(unsharp)
else
return unsharp
end
else
return src
end
end
function data_augmentation.blur(src, p, size, sigma_min, sigma_max)
size = size or "3"
filters = utils.split(size, ",")
for i = 1, #filters do
local s = tonumber(filters[i])
filters[i] = s
end
if torch.uniform() < p then
local src, conversion = iproc.byte2float(src)
local kernel_size = filters[torch.random(1, #filters)]
local sigma
if sigma_min == sigma_max then
sigma = sigma_min
else
sigma = torch.uniform(sigma_min, sigma_max)
end
local kernel = iproc.gaussian2d(kernel_size, sigma)
local dest = image.convolve(src, kernel, 'same')
if conversion then
dest = iproc.float2byte(dest)
end
return dest
else
return src
end
end
function data_augmentation.pairwise_scale(x, y, p, scale_min, scale_max)
if torch.uniform() < p then
assert(x:size(2) == y:size(2) and x:size(3) == y:size(3))
local scale = torch.uniform(scale_min, scale_max)
local h = math.floor(x:size(2) * scale)
local w = math.floor(x:size(3) * scale)
local filters = {"Lanczos", "Catrom"}
local x_filter = filters[torch.random(1, 2)]
x = iproc.scale(x, w, h, x_filter)
y = iproc.scale(y, w, h, "Triangle")
return x, y
else
return x, y
end
end
function data_augmentation.pairwise_rotate(x, y, p, r_min, r_max)
if torch.uniform() < p then
assert(x:size(2) == y:size(2) and x:size(3) == y:size(3))
local r = torch.uniform(r_min, r_max) / 360.0 * math.pi
x = iproc.rotate(x, r)
y = iproc.rotate(y, r)
return x, y
else
return x, y
end
end
function data_augmentation.pairwise_negate(x, y, p)
if torch.uniform() < p then
assert(x:size(2) == y:size(2) and x:size(3) == y:size(3))
x = iproc.negate(x)
y = iproc.negate(y)
return x, y
else
return x, y
end
end
function data_augmentation.pairwise_negate_x(x, y, p)
if torch.uniform() < p then
assert(x:size(2) == y:size(2) and x:size(3) == y:size(3))
x = iproc.negate(x)
return x, y
else
return x, y
end
end
function data_augmentation.pairwise_flip(x, y)
local flip = torch.random(1, 4)
local tr = torch.random(1, 2)
local x, conversion = iproc.byte2float(x)
y = iproc.byte2float(y)
x = x:contiguous()
y = y:contiguous()
if tr == 1 then
-- pass
elseif tr == 2 then
x = x:transpose(2, 3):contiguous()
y = y:transpose(2, 3):contiguous()
end
if flip == 1 then
x = iproc.hflip(x)
y = iproc.hflip(y)
elseif flip == 2 then
x = iproc.vflip(x)
y = iproc.vflip(y)
elseif flip == 3 then
x = iproc.hflip(iproc.vflip(x))
y = iproc.hflip(iproc.vflip(y))
elseif flip == 4 then
end
if conversion then
x = iproc.float2byte(x)
y = iproc.float2byte(y)
end
return x, y
end
function data_augmentation.shift_1px(src)
-- reducing the even/odd issue in nearest neighbor scaler.
local direction = torch.random(1, 4)
local x_shift = 0
local y_shift = 0
if direction == 1 then
x_shift = 1
y_shift = 0
elseif direction == 2 then
x_shift = 0
y_shift = 1
elseif direction == 3 then
x_shift = 1
y_shift = 1
elseif flip == 4 then
x_shift = 0
y_shift = 0
end
local w = src:size(3) - x_shift
local h = src:size(2) - y_shift
w = w - (w % 4)
h = h - (h % 4)
local dest = iproc.crop(src, x_shift, y_shift, x_shift + w, y_shift + h)
return dest
end
function data_augmentation.flip(src)
local flip = torch.random(1, 4)
local tr = torch.random(1, 2)
local src, conversion = iproc.byte2float(src)
local dest
src = src:contiguous()
if tr == 1 then
-- pass
elseif tr == 2 then
src = src:transpose(2, 3):contiguous()
end
if flip == 1 then
dest = iproc.hflip(src)
elseif flip == 2 then
dest = iproc.vflip(src)
elseif flip == 3 then
dest = iproc.hflip(iproc.vflip(src))
elseif flip == 4 then
dest = src
end
if conversion then
dest = iproc.float2byte(dest)
end
return dest
end
local function test_blur()
torch.setdefaulttensortype("torch.FloatTensor")
local image =require 'image'
local src = image.lena()
image.display({image = src, min=0, max=1})
local dest = data_augmentation.blur(src, 1.0, "3,5", 0.5, 0.6)
image.display({image = dest, min=0, max=1})
dest = data_augmentation.blur(src, 1.0, "3", 1.0, 1.0)
image.display({image = dest, min=0, max=1})
dest = data_augmentation.blur(src, 1.0, "5", 0.75, 0.75)
image.display({image = dest, min=0, max=1})
end
--test_blur()
return data_augmentation