[Telemetry] Migrate bitmap.py from bitmaptools.cc to numpy

tools/telemetry/telemetry/image_processing/image_util.py

Index: tools/telemetry/telemetry/image_processing/image_util.py
diff --git a/tools/telemetry/telemetry/image_processing/image_util.py b/tools/telemetry/telemetry/image_processing/image_util.py
new file mode 100644
index 0000000000000000000000000000000000000000..478661f5c98d82c2f321b07352df52cf46564734
--- /dev/null
+++ b/tools/telemetry/telemetry/image_processing/image_util.py
@@ -0,0 +1,114 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Provides implementations of basic image processing functions.
+
+Implements basic image processing functions, such as reading/writing images,
+cropping, finding the bounding box of a color and diffing images.
+
+When numpy is present, image_util_numpy_impl is used for the implementation of
+this interface. The old bitmap implementation (image_util_bitmap_impl) is used
+as a fallback when numpy is not present."""
+
+import base64
+
+from telemetry.util import external_modules
+
+np = external_modules.ImportOptionalModule('numpy')
+
+if np is None:
+  from telemetry.image_processing import image_util_bitmap_impl
+  impl = image_util_bitmap_impl
+else:
+  from telemetry.image_processing import image_util_numpy_impl
+  impl = image_util_numpy_impl
+
+
+def Channels(image):
+  """Number of color channels in the image."""
+  return impl.Channels(image)
+
+def Width(image):
+  """Width of the image."""
+  return impl.Width(image)
+
+def Height(image):
+  """Height of the image."""
+  return impl.Height(image)
+
+def Pixels(image):
+  """Flat RGB pixel array of the image."""
+  return impl.Pixels(image)
+
+def GetPixelColor(image, x, y):
+  """Returns a RgbaColor for the pixel at (x, y)."""
+  return impl.GetPixelColor(image, x, y)
+
+def WritePngFile(image, path):
+  return impl.WritePngFile(image, path)
+
+def FromRGBPixels(width, height, pixels, bpp=3):
+  """Create an image from an array of rgb pixels.
+
+  Ignores alpha channel if present.
+
+  Args:
+    width, height: int, the width and height of the image.
+    pixels: The flat array of pixels in the form of [r,g,b[,a],r,g,b[,a],...]
+    bpp: 3 for RGB, 4 for RGBA."""
+  return impl.FromRGBPixels(width, height, pixels, bpp)
+
+def FromPng(png_data):
+  """Create an image from raw PNG data."""
+  return impl.FromPng(png_data)
+
+def FromPngFile(path):
+  """Create an image from a PNG file.
+
+  Args:
+    path: The path to the PNG file."""
+  return impl.FromPngFile(path)
+
+def FromBase64Png(base64_png):
+  """Create an image from raw PNG data encoded in base64."""
+  return FromPng(base64.b64decode(base64_png))
+
+def AreEqual(image1, image2, tolerance=0, likely_equal=True):
+  """Determines whether two images are identical within a given tolerance.
+  Setting likely_equal to False enables short-circuit equality testing, which
+  is about 2-3x slower for equal images, but can be image height times faster
+  if the images are not equal."""
+  return impl.AreEqual(image1, image2, tolerance, likely_equal)
+
+def Diff(image1, image2):
+  """Returns a new image that represents the difference between this image
+  and another image."""
+  return impl.Diff(image1, image2)
+
+def GetBoundingBox(image, color, tolerance=0):
+  """Finds the minimum box surrounding all occurrences of bgr |color|.
+
+  Ignores the alpha channel.
+
+  Args:
+    color: RbgaColor, bounding box color.
+    tolerance: int, per-channel tolerance for the bounding box color.
+
+  Returns:
+    (top, left, width, height), match_count"""
+  return impl.GetBoundingBox(image, color, tolerance)
+
+def Crop(image, left, top, width, height):
+  """Crops the current image down to the specified box."""
+  return impl.Crop(image, left, top, width, height)
+
+def GetColorHistogram(image, ignore_color=None, tolerance=0):
+  """Computes a histogram of the pixel colors in this image.
+  Args:
+    ignore_color: An RgbaColor to exclude from the bucket counts.
+    tolerance: A tolerance for the ignore_color.
+
+  Returns:
+    A ColorHistogram namedtuple with 256 integers in each field: r, g, and b."""
+  return impl.GetColorHistogram(image, ignore_color, tolerance)