Allow using pictures as decorations

* face_decor.py: Only preserve decorating eyebrows
* rotate.py: Demonstration of rotating pictures
* pic_on_pic.py: Test of putting 4-channel pictures on RGB background
* thuglife_resized.png: Square version of Thug Life's sunglasses, in order
	to avoid stripping in rotation
* face_thuglife.py: Created. To put sunglasses in either pictures or in
	the view of webcam

face_decor.py

@@ -19,9 +19,10 @@ def do_decor(frame):
         top_lip=np.array(face_landmarks["top_lip"],np.int32)
         bottom_lip=np.array(face_landmarks["bottom_lip"],np.int32)
         frame=cv2.fillPoly(frame,[k*eyebrow_l,k*eyebrow_r],(0xFF,0xFF,0xFF))
-        frame=cv2.fillPoly(frame,[k*nose],(0,0x80,0xFF))
-        frame=cv2.fillPoly(frame,[k*bottom_lip],(0,0,0xFF))
-        frame=cv2.fillPoly(frame,[k*top_lip],(0,0xFF,0))
+        #frame=cv2.fillPoly(frame,[k*nose],(0,0x80,0xFF))
+        mouth_color=(0x3E,0x51,0xFC)
+        #frame=cv2.fillPoly(frame,[k*bottom_lip],mouth_color)
+        #frame=cv2.fillPoly(frame,[k*top_lip],mouth_color)
     return frame
 
 while webcam.isOpened():

face_thuglife.py

@@ -0,0 +1,95 @@
+#!/usr/bin/env python3
+import numpy as np
+import face_recognition as fr
+from os.path import exists,splitext
+import sys
+import cv2
+
+thuglife_file="./thuglife_resized.png"
+assert(exists(thuglife_file))
+# The second argument cv2.IMREAD_UNCHANGED is extremely important because it
+# supports reading pictures using alpha channel
+thuglife=cv2.imread("thuglife_resized.png",cv2.IMREAD_UNCHANGED)
+
+assert(thuglife.shape[2]==4)    # Must have alpha channel
+
+# determines whether to print debug messages in the session or not
+debug=False
+
+k=1
+
+def put_sunglasses(frame,pic,mid,angle):
+    h,w=pic.shape[0:2]
+    coeff=0.63
+    y=int(mid[1]-h/2)
+    x=int(mid[0]-coeff*w)
+    M=cv2.getRotationMatrix2D((w/2,h/2),angle,1)
+    pic=cv2.warpAffine(pic,M,(w,h))
+    a,b=y+h,x+w
+    roi=frame[y:a,x:b]
+    for i,row in enumerate(pic):
+        for j,pix in enumerate(row):
+            try:
+                alpha=pix[3]/0xFF
+                vec=np.array([alpha,1-alpha])
+                mat=np.array([pix[0:3],roi[i][j]],dtype=np.int8).T
+                mixed=mat.dot(vec)
+                assert(len(mixed.shape)==1 and mixed.shape[0]==3)
+                roi[i][j]=mixed
+            except IndexError:
+                continue
+    frame[y:a,x:b]=roi
+    return frame
+
+def mark_eye(frame):
+    small=cv2.resize(frame,(0,0),fx=1/k,fy=1/k)
+    rgb_frame=small[:,:,::-1]
+    all_landmarks=fr.face_landmarks(rgb_frame)
+    slopes=[]
+    mids=[]
+    for i,landmarks in enumerate(all_landmarks):
+        pt1=np.array(landmarks["left_eye"][0],dtype=np.int32)
+        pt2=np.array(landmarks["right_eye"][3],dtype=np.int32)
+        mids.append(np.array(k*(pt1+pt2)/2,dtype=np.int32))
+        diff=pt2-pt1
+        width=int(k*np.sqrt(np.sum(np.square(diff))))
+        ratio=width/thuglife.shape[1]*3/2
+        slopes.append(diff[1]/diff[0])
+        #frame=cv2.line(frame,(pt1[0]*k,pt1[1]*k),(pt2[0]*k,pt2[1]*k),
+        #        (0xFF,0,0),2,8)
+        #frame=cv2.rectangle(frame,(pt1[0]*k,pt1[1]*k),(pt2[0]*k,pt2[1]*k),
+        #        (0,0xFF,0),2)
+        pic=cv2.resize(thuglife,(0,0),fx=ratio,fy=ratio)
+        frame=put_sunglasses(frame,pic,mids[i],-np.arctan(slopes[i])/np.pi*180)
+    if debug and len(slopes)>0:
+        print("Slopes: {}".format(slopes))
+        print("Angles: {}".format(-np.arctan(slopes)/np.pi*180))
+        print("Midpoints: {}".format([m.tolist() for m in mids]))
+    return frame
+
+def decor_img(name):
+    img=cv2.imread(name)
+    img=mark_eye(img)
+    out="%s_thuglife.png" % splitext(name)[0]
+    print("Saved to %s" % out)
+    cv2.imwrite(out,img)
+
+argc=len(sys.argv)
+if argc>=2:
+    if not exists(sys.argv[1]):
+        print("%s: No such file or directory" % sys.argv[1])
+        exit(-1)
+    decor_img(sys.argv[1])
+    exit(0)
+
+webcam=cv2.VideoCapture(0)
+
+while webcam.isOpened():
+    ret,frame=webcam.read()
+    if ret==False:
+        break
+    frame=cv2.flip(frame,1)
+    frame=mark_eye(frame)
+    cv2.imshow("Thug Life",frame)
+    if cv2.waitKey(1) & 0xFF == ord('q'):
+        break

pic_on_pic.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python3
+import cv2
+import numpy as np
+import face_recognition as fr
+
+background=cv2.imread("known_people/Barack_Obama.jpg",cv2.IMREAD_COLOR)
+foreground=cv2.imread("thuglife.png",cv2.IMREAD_UNCHANGED)
+
+[face]=fr.face_locations(background[:,:,::-1])
+top,right,left,bottom=face
+
+assert(foreground.shape[2]==4)  # Assume foreground image has alpha channel
+
+height=foreground.shape[0]
+width=foreground.shape[1]
+
+a=top
+b=left
+
+c=a+height
+d=b+width
+
+roi=background[a:c,b:d]
+for i,row in enumerate(foreground):
+    for j,pix in enumerate(row):
+        alpha=pix[3]/0xFF
+        mixed=pix[0:3]*alpha+roi[i][j]*(1-alpha).astype(np.int8)
+        roi[i][j]=mixed
+
+background[a:c,b:d]=roi
+
+cv2.imshow("Mixed",background)
+cv2.waitKey(0)

rotate.py

@@ -0,0 +1,26 @@
+#!/usr/bin/env python3
+import sys
+import cv2
+import numpy as np
+
+argc=len(sys.argv)
+if argc<3:
+    print("usage: %s image_file counter_clockwise" % sys.argv[0])
+    exit(-1)
+
+degree=float(sys.argv[2])
+rad=degree*np.pi/180.0
+
+image=cv2.imread(sys.argv[1],cv2.IMREAD_UNCHANGED)
+
+height,width=image.shape[0:2]   # Get the shape
+
+print("w=%d,h=%d" % (width,height))
+
+M=cv2.getRotationMatrix2D((width/2,height/2),degree,1)
+
+
+image=cv2.warpAffine(image,M,(width,height))
+
+cv2.imshow("Rotated",image)
+cv2.waitKey(0)