CVImage class in imagepipeline module.

TODO: remove all image manipulation code from GameModel class. Moving all the OpenCV image manipulation actions to the CVImage class would make the GameModel procedures more legible.
TODO: abstract multi-step processes in GameModel class as an ImagePipeline. The purpose is to improve testability by making each manipulation action in CVImage to result in a series of images and data structures.

imagepipeline.py

@@ -0,0 +1,57 @@
+import cv2
+import numpy as np
+
+class CVImage:
+    def __init__(self, label="", img=None, iscolor=False):
+        self.label = label
+        self.image = img
+        self.iscolor = iscolor
+
+    def load(self, filename, color=False, label=None):
+        self.image = cv2.imread(filename, int(color))
+        if label: self.label = label
+
+    def copy(self):
+        return np.copy(self.image)
+
+##    def snip(self, point, width_height):
+##        return self.image[self.point[0]:self.point[0]+self.width_height[0],
+##                          self.point[1]:self.point[1]+self.width_height[1]]
+
+    def snip(self, rect):
+        assert all((len(rect)==2, len(rect[0])==2, len(rect[1])==2)) #((x,y),(w,h))
+        return self.image[self.rect[0][0]:self.rect[0][1],
+                          self.rect[1][0]:self.rect[1][1]]
+
+    def mask(self, rect, mask_color=None, nonmask_color=None):
+        assert all((len(rect)==2, len(rect[0])==2, len(rect[1])==2)) #((x,y),(w,h))
+        if mask_color is None:
+            mask_color = (0, 0, 0) if self.iscolor else 0
+        if nonmask_color is None:
+            nonnmask_color = (255, 255, 255) if self.iscolor else 255
+        mask = np.full(self.image.shape, nonmask_color, dtype=np.uint8)
+        cv2.rectangle(mask, *rect, color=mask_color, thickness=cv2.FILLED)
+        return cv2.bitwise_and(self.image, mask)
+
+    def sift_clusters(self, cluster_radius):
+        sift = cv2.SIFT_create()
+        keypoints, descriptions = sift.detectAndCompute(self.image, None)
+        return pointcluster.cluster_set([k.pt for k in keypoints], cluster_radius)
+
+    def set_blob_params(self, minThreshold = 10, maxThreshold = 200,
+                     minArea = None, maxArea = None,
+                     minCircularity = None, maxCircularity = None,
+                     minConvexity = None, maxConvexity = None,
+                     minInertiaRatio = None, maxInertiaRatio = None):
+        p = cv2.SimpleBlobDetector_Params()
+        
+
+    def blob_detect(self, params=None):
+        pass
+    
+
+class ImagePipeline:
+    def __init__(self):
+        pass
+
+