Initial commit

equi_to_cube.py

@@ -0,0 +1,119 @@
+from __future__ import print_function
+import sys
+import os.path
+from PIL import Image
+from math import pi,sin,cos,tan,atan2,hypot,floor
+from numpy import clip
+
+# get x,y,z coords from out image pixels coords
+# i,j are pixel coords
+# face is face number
+# edge is edge length
+def outImgToXYZ(i,j,face,edge):
+    a = 2.0*float(i)/edge
+    b = 2.0*float(j)/edge
+    if face==0: # back
+        (x,y,z) = (-1.0, 1.0-a, 3.0 - b)
+    elif face==1: # left
+        (x,y,z) = (a-3.0, -1.0, 3.0 - b)
+    elif face==2: # front
+        (x,y,z) = (1.0, a - 5.0, 3.0 - b)
+    elif face==3: # right
+        (x,y,z) = (7.0-a, 1.0, 3.0 - b)
+    elif face==4: # top
+        (x,y,z) = (b-1.0, a -5.0, 1.0)
+    elif face==5: # bottom
+        (x,y,z) = (5.0-b, a-5.0, -1.0)
+    return (x,y,z)
+
+# convert using an inverse transformation
+def convertBack(imgIn,imgOut):
+    inSize = imgIn.size
+    outSize = imgOut.size
+    inPix = imgIn.load()
+    outPix = imgOut.load()
+    edge = inSize[0]/4   # the length of each edge in pixels
+    for i in range(outSize[0]):
+        face = int(i/edge) # 0 - back, 1 - left 2 - front, 3 - right
+        if face==2:
+            rng = range(0,int(edge*3))
+        else:
+            rng = range(int(edge), int(edge) * 2)
+
+        for j in rng:
+            if j<edge:
+                face2 = 4 # top
+            elif j>=2*edge:
+                face2 = 5 # bottom
+            else:
+                face2 = face
+
+            (x,y,z) = outImgToXYZ(i,j,face2,edge)
+            theta = atan2(y,x) # range -pi to pi
+            r = hypot(x,y)
+            phi = atan2(z,r) # range -pi/2 to pi/2
+            # source img coords
+            uf = ( 2.0*edge*(theta + pi)/pi )
+            vf = ( 2.0*edge * (pi/2 - phi)/pi)
+            # Use bilinear interpolation between the four surrounding pixels
+            ui = floor(uf)  # coord of pixel to bottom left
+            vi = floor(vf)
+            u2 = ui+1       # coords of pixel to top right
+            v2 = vi+1
+            mu = uf-ui      # fraction of way across pixel
+            nu = vf-vi
+            # Pixel values of four corners
+            # import sys
+            # print('inPix ->', inPix)
+            # print('ui ->', ui)
+            # print('inSize[0]', inSize[0])
+            # bar = clip(vi,0,inSize[1]-1)
+            # print('bar ->', bar, type(bar), int(bar))
+            # baz = ui % inSize[0]
+            # print('baz ->', baz, type(baz))
+            # foo = inPix[ui % inSize[0], bar]
+            # sys.exit(-1)
+            A = inPix[ui % inSize[0],int(clip(vi,0,inSize[1]-1))]
+            B = inPix[u2 % inSize[0],int(clip(vi,0,inSize[1]-1))]
+            C = inPix[ui % inSize[0],int(clip(v2,0,inSize[1]-1))]
+            D = inPix[u2 % inSize[0],int(clip(v2,0,inSize[1]-1))]
+            # interpolate
+            (r,g,b) = (
+              A[0]*(1-mu)*(1-nu) + B[0]*(mu)*(1-nu) + C[0]*(1-mu)*nu+D[0]*mu*nu,
+              A[1]*(1-mu)*(1-nu) + B[1]*(mu)*(1-nu) + C[1]*(1-mu)*nu+D[1]*mu*nu,
+              A[2]*(1-mu)*(1-nu) + B[2]*(mu)*(1-nu) + C[2]*(1-mu)*nu+D[2]*mu*nu )
+
+            outPix[i,j] = (int(round(r)),int(round(g)),int(round(b)))
+
+imgIn = Image.open(sys.argv[1])
+inSize = imgIn.size
+i1 = inSize[0]
+imgOut = Image.new("RGB",(inSize[0],int(inSize[0]*3/4)),"black")
+convertBack(imgIn,imgOut)
+imgOut.save(sys.argv[1].split('.')[0]+"_cubemap.png")
+
+file_extension = ".jpg"
+
+name_map = [ \
+     ["", "", "py", ""],
+     ["nz", "nx", "pz", "px"],
+     ["", "", "ny", ""]]
+
+try:
+    width, height = imgOut.size
+
+    cube_size = width / 4
+
+    filelist = []
+    for row in range(3):
+        for col in range(4):
+            if name_map[row][col] != "":
+                sx = cube_size * col
+                sy = cube_size * row
+                fn = name_map[row][col] + file_extension
+                filelist.append(fn)
+                imgOut.crop((sx, sy, sx + cube_size, sy + cube_size)).save(fn)
+
+
+except IOError:
+    pass