initial version

epd/image_processor.py

@@ -0,0 +1,96 @@
+from PIL import Image
+
+def getErr(r,g,b,stdCol):
+    r-=stdCol[0]
+    g-=stdCol[1]
+    b-=stdCol[2]
+    return r*r + g*g + b*b
+
+def getNear(r,g,b, curPal):
+    ind=0
+    err=getErr(r,g,b,curPal[0])
+    for i in range(1,len(curPal)):
+        cur=getErr(r,g,b,curPal[i])
+        if (cur<err):
+            err=cur
+            ind=i
+    return ind
+
+def addVal(c,r,g,b,k):
+    return[c[0]+(r*k)/32,c[1]+(g*k)/32,c[2]+(b*k)/32]
+
+def procImg(img, dW, dH, dX, dY, palInd, isLvl, isRed, palArr):
+    if isRed and ((palInd & 1) == 0):
+        raise ValueError('This white-black display')
+
+    if not isRed:
+        palInd = palInd & 0xFE
+
+    curPal = palArr[palInd]
+
+    sW = img.width
+    sH = img.height
+
+    pDst = Image.new('RGB', (dW, dH))
+    pixels = pDst.load()
+
+    if isLvl:
+        # Level-based processing
+        for j in range(dH):
+            y = dY + j
+            for i in range(dW):
+                x = dX + i
+                if 0 <= x < sW and 0 <= y < sH:
+                    r, g, b = img.getpixel((x, y))
+                    color_index = getNear(r, g, b, curPal)
+                    pixels[i, j] = tuple(curPal[color_index])
+                else:
+                    pixels[i, j] = tuple(curPal[(i + j) % 2]) # checkerboard for out of bounds
+    else:
+        # Dithering
+        errArr = [[[0, 0, 0] for _ in range(dW)] for _ in range(2)]
+        aInd = 0
+        bInd = 1
+
+        for j in range(dH):
+            y = dY + j
+            aInd, bInd = bInd, aInd # swap buffers
+            for i in range(dW):
+                errArr[bInd][i] = [0,0,0]
+
+            for i in range(dW):
+                x = dX + i
+                if 0 <= x < sW and 0 <= y < sH:
+                    old = errArr[aInd][i]
+                    r_orig, g_orig, b_orig = img.getpixel((x, y))
+                    r = r_orig + old[0]
+                    g = g_orig + old[1]
+                    b = b_orig + old[2]
+
+                    color_index = getNear(r, g, b, curPal)
+                    colVal = curPal[color_index]
+                    pixels[i, j] = tuple(colVal)
+
+                    r_err = r - colVal[0]
+                    g_err = g - colVal[1]
+                    b_err = b - colVal[2]
+
+                    # Propagate error (Floyd-Steinberg-like)
+                    if i == 0:
+                        errArr[bInd][i]     = addVal(errArr[bInd][i],     r_err, g_err, b_err, 7.0)
+                        if dW > 1:
+                            errArr[bInd][i+1]   = addVal(errArr[bInd][i+1],   r_err, g_err, b_err, 2.0)
+                            errArr[aInd][i+1]   = addVal(errArr[aInd][i+1],   r_err, g_err, b_err, 7.0)
+                    elif i == dW - 1:
+                        errArr[bInd][i-1]   = addVal(errArr[bInd][i-1],   r_err, g_err, b_err, 7.0)
+                        errArr[bInd][i]     = addVal(errArr[bInd][i],     r_err, g_err, b_err, 9.0)
+                    else:
+                        errArr[bInd][i-1]   = addVal(errArr[bInd][i-1],   r_err, g_err, b_err, 3.0)
+                        errArr[bInd][i]     = addVal(errArr[bInd][i],     r_err, g_err, b_err, 5.0)
+                        errArr[bInd][i+1]   = addVal(errArr[bInd][i+1],   r_err, g_err, b_err, 1.0)
+                        errArr[aInd][i+1]   = addVal(errArr[aInd][i+1],   r_err, g_err, b_err, 7.0)
+
+                else:
+                    pixels[i, j] = tuple(curPal[(i + j) % 2]) # checkerboard
+
+    return pDst