getAroundPixelValues

def getCoordPixel(pixels, width, height, index, x=0, y=0):
    bx = (index % width) + x
    by = (index // height) + y
    ex = -1 < bx < width and -1 < by < height
    indexB = index + x + (y * width) if ex else None
    pixelB = pixels[indexB] if indexB else None
    return pixelB

index = 8
width = 4
height = 4
pixels = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]

print '[ \][x0][x1][x2][x3]'
print '[y0]   0,  1,  2,  3'
print '[y1]   4,  5,  6,  7'
print '[y2]   8,  9, 10, 11'
print '[y3]  12, 13, 14, 15'

print ''
print 'index:', index
print 'R=Right, B=Bottom, L=Left, T=Top'
print '   R:', getCoordPixel(pixels, width, height, index, x= 1, y= 0) # 9
print '   B:', getCoordPixel(pixels, width, height, index, x= 0, y= 1) # 12
print '   L:', getCoordPixel(pixels, width, height, index, x=-1, y= 0) # None
print '   T:', getCoordPixel(pixels, width, height, index, x= 0, y=-1) # 4
print '  TR:', getCoordPixel(pixels, width, height, index, x= 1, y=-1) # 5
print '  BR:', getCoordPixel(pixels, width, height, index, x= 1, y= 1) # 13
print '  BL:', getCoordPixel(pixels, width, height, index, x=-1, y= 1) # None
print '  TL:', getCoordPixel(pixels, width, height, index, x=-1, y=-1) # None
print '  RR:', getCoordPixel(pixels, width, height, index, x= 2, y= 0) # 10
print '  BB:', getCoordPixel(pixels, width, height, index, x= 0, y= 2) # None
print '  LL:', getCoordPixel(pixels, width, height, index, x=-2, y= 0) # None
print '  TT:', getCoordPixel(pixels, width, height, index, x= 0, y=-2) # 0
print 'TTRR:', getCoordPixel(pixels, width, height, index, x= 2, y=-2) # 2
print 'BBRR:', getCoordPixel(pixels, width, height, index, x= 2, y= 2) # None
print 'BBLL:', getCoordPixel(pixels, width, height, index, x=-2, y= 2) # None
print 'TTLL:', getCoordPixel(pixels, width, height, index, x=-2, y=-2) # None