Add -white_noise option

post-processing for anime screencap.

assets/index.html

@@ -52,6 +52,14 @@
         <label><input type="radio" name="scale" value="1"> 1.6x</label>
         <label><input type="radio" name="scale" value="2"> 2x</label>
       </fieldset>
+      <fieldset>
+        <legend>Adding white noise</legend>
+        <label><input type="radio" name="white_noise" value="0" checked="checked">Off</label>
+        <label><input type="radio" name="white_noise" value="1">On</label>
+	<div class="help">
+	  To denoise without unnaturalness in an anime screencap.
+	</div>
+      </fieldset>
       <input type="submit"/>
     </form>
     <div class="help">

assets/index.ja.html

@@ -49,6 +49,14 @@
         <label><input type="radio" name="scale" value="1"> 1.6x</label>
         <label><input type="radio" name="scale" value="2"> 2x</label>
       </fieldset>
+      <fieldset>
+        <legend>ホワイトノイズ付加</legend>
+        <label><input type="radio" name="white_noise" value="0" checked="checked">Off</label>
+        <label><input type="radio" name="white_noise" value="1">On</label>
+	<div class="help">
+	  アニメのキャプチャ画像をノイズ除去したときの不自然さを低減します。
+	</div>
+      </fieldset>
       <input type="submit" value="実行"/>
     </form>
     <div class="help">

assets/index.ru.html

@@ -51,6 +51,14 @@
         <label><input type="radio" name="scale" value="1"> 1.6x</label>
         <label><input type="radio" name="scale" value="2"> 2x</label>
       </fieldset>
+      <fieldset>
+        <legend>Adding white noise</legend>
+        <label><input type="radio" name="white_noise" value="0" checked="checked">Off</label>
+        <label><input type="radio" name="white_noise" value="1">On</label>
+	<div class="help">
+	  To denoise without unnaturalness in an anime screencap.
+	</div>
+      </fieldset>
       <input type="submit"/>
     </form>
     <div class="help">

lib/iproc.lua

@@ -84,6 +84,30 @@ function iproc.padding(img, w1, w2, h1, h2)
    flow[2]:add(-w1)
    return image.warp(img, flow, "simple", false, "clamp")
 end
+function iproc.white_noise(src, std, rgb_weights, gamma)
+   gamma = gamma or 0.454545
+   local conversion
+   src, conversion = iproc.byte2float(src)
+   std = std or 0.01
+
+   local noise = torch.Tensor():resizeAs(src):normal(0, std)
+   if rgb_weights then 
+      noise[1]:mul(rgb_weights[1])
+      noise[2]:mul(rgb_weights[2])
+      noise[3]:mul(rgb_weights[3])
+   end
+
+   local dest
+   if gamma ~= 0 then
+      dest = src:clone():pow(gamma):add(noise):pow(1.0 / gamma)
+   else
+      dest = src + noise
+   end
+   if conversion then
+      dest = iproc.float2byte(dest)
+   end
+   return dest
+end
 
 local function test_conversion()
    local a = torch.linspace(0, 255, 256):float():div(255.0)

waifu2x.lua

@@ -58,6 +58,9 @@ local function convert_image(opt)
    else
       error("undefined method:" .. opt.method)
    end
+   if opt.white_noise == 1 then
+      new_x = iproc.white_noise(new_x, opt.white_noise_std, {1.0, 0.8, 1.0})
+   end
    image_loader.save_png(opt.o, new_x, alpha, opt.depth)
    print(opt.o .. ": " .. (sys.clock() - t) .. " sec")
 end
@@ -138,6 +141,10 @@ local function convert_frames(opt)
 	 else
 	    error("undefined method:" .. opt.method)
 	 end
+	 if opt.white_noise == 1 then
+	    new_x = iproc.white_noise(new_x, opt.white_noise_std, {1.0, 0.8, 1.0})
+	 end
+
 	 local output = nil
 	 if opt.o == "(auto)" then
 	    local name = path.basename(lines[i])
@@ -175,6 +182,8 @@ local function waifu2x()
    cmd:option("-resume", 0, "skip existing files (0|1)")
    cmd:option("-thread", -1, "number of CPU threads")
    cmd:option("-tta", 0, '8x slower and slightly high quality (0|1)')
+   cmd:option("-white_noise", 0, 'adding white noise to output image (0|1)')
+   cmd:option("-white_noise_std", 0.0055, 'standard division of white noise')
    
    local opt = cmd:parse(arg)
    if opt.thread > 0 then

web.lua

@@ -142,6 +142,7 @@ function APIHandler:post()
    local x, alpha, blob = get_image(self)
    local scale = tonumber(self:get_argument("scale", "0"))
    local noise = tonumber(self:get_argument("noise", "0"))
+   local white_noise = tonumber(self:get_argument("white_noise", "0"))
    local style = self:get_argument("style", "art")
    if style ~= "art" then
       style = "photo" -- style must be art or photo
@@ -169,6 +170,9 @@ function APIHandler:post()
 					    "Jinc")
 	    end
 	 end
+	 if white_noise == 1 then
+	    x = iproc.white_noise(x, 0.005, {1.0, 0.8, 1.0})
+	 end
       end
       local name = uuid() .. ".png"
       local blob, len = image_loader.encode_png(x, alpha)
@@ -179,7 +183,7 @@ function APIHandler:post()
    else
       if not x then
 	 self:set_status(400)
-	 self:write("ERROR: unsupported image format.")
+	 self:write("ERROR: An error occurred. (unsupported image format/connection timeout/file is too large)")
       else
 	 self:set_status(400)
 	 self:write("ERROR: image size exceeds maximum allowable size.")