diff --git a/wip/Tune-canvas-randomisation.patch b/wip/Tune-canvas-randomisation.patch
new file mode 100644
index 00000000..425a1cab
--- /dev/null
+++ b/wip/Tune-canvas-randomisation.patch
@@ -0,0 +1,64 @@
+From: csagan5 <32685696+csagan5@users.noreply.github.com>
+Date: Mon, 18 Jun 2018 09:03:52 +0200
+Subject: Tune canvas randomisation
+
+Randomise RGB for each pixel, change value up to to 8%
+---
+ .../blink/renderer/core/offscreencanvas/offscreen_canvas.cc  |  1 -
+ .../modules/canvas/canvas2d/base_rendering_context_2d.cc     |  2 +-
+ .../blink/renderer/platform/graphics/image_data_buffer.cc    | 12 ++++++------
+ 3 files changed, 7 insertions(+), 8 deletions(-)
+
+diff --git a/third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.cc b/third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.cc
+--- a/third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.cc
++++ b/third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.cc
+@@ -403,7 +403,6 @@ ScriptPromise OffscreenCanvas::convertToBlob(ScriptState* script_state,
+     CanvasAsyncBlobCreator* async_creator = CanvasAsyncBlobCreator::Create(
+         snapshot, encoding_mime_type, start_time,
+         ExecutionContext::From(script_state), resolver);
+-
+     async_creator->ScheduleAsyncBlobCreation(options.quality());
+     return resolver->Promise();
+   } else {
+diff --git a/third_party/blink/renderer/modules/canvas/canvas2d/base_rendering_context_2d.cc b/third_party/blink/renderer/modules/canvas/canvas2d/base_rendering_context_2d.cc
+--- a/third_party/blink/renderer/modules/canvas/canvas2d/base_rendering_context_2d.cc
++++ b/third_party/blink/renderer/modules/canvas/canvas2d/base_rendering_context_2d.cc
+@@ -1621,7 +1621,7 @@ ImageData* BaseRenderingContext2D::getImageData(
+   scoped_refptr<StaticBitmapImage> snapshot = GetImage(kPreferNoAcceleration);
+ 
+   //TODO: calculate some random value and use it to shuffle pixel data in 'snapshot'
+-  // it should StaticBitmapImage somehow
++  // it should be a StaticBitmapImage somehow
+ 
+   if (!StaticBitmapImage::ConvertToArrayBufferContents(
+           snapshot, contents, image_data_rect, color_params, IsAccelerated())) {
+diff --git a/third_party/blink/renderer/platform/graphics/image_data_buffer.cc b/third_party/blink/renderer/platform/graphics/image_data_buffer.cc
+--- a/third_party/blink/renderer/platform/graphics/image_data_buffer.cc
++++ b/third_party/blink/renderer/platform/graphics/image_data_buffer.cc
+@@ -134,17 +134,17 @@ void ImageDataBuffer::shuffleSubchannelColorData() const {
+   // second random number (for y/height)
+   double shuffleY = base::RandDouble();
+ 
+-  // calculate amounts to change per component
+-  double shuffleR = shuffleX - 0.5, shuffleG = shuffleY - 0.5, shuffleB = (shuffleX + shuffleY)/2 - 0.5;
+-  shuffleR *= 0.03;
+-  shuffleG *= 0.03;
+-  shuffleB *= 0.03;
+-
+   auto colorType = pixmap_.colorType();
+ 
+   // calculate random coordinates using bisection
+   auto currentW = w, currentH = h;
+   for(;pixels >= 0; pixels--) {
++    // calculate amounts to change per RGB component, +/- 4% max
++    double shuffleR = base::RandDouble() - 0.5, shuffleG = base::RandDouble() - 0.5, shuffleB = base::RandDouble() - 0.5;
++    shuffleR *= 0.08;
++    shuffleG *= 0.08;
++    shuffleB *= 0.08;
++
+     int x = currentW * shuffleX, y = currentH * shuffleY;
+ 
+     // manipulate pixel data to slightly change the R, G, B components
+-- 
+2.7.4
+