fiber_utils.py 文件源码

def measure_background(image, Fibers, width=30, niter=3, order=3):
    t = []
    a,b = image.shape
    ygrid,xgrid = np.indices(image.shape)
    ygrid = 1. * ygrid.ravel() / a
    xgrid = 1. * xgrid.ravel() / b
    image = image.ravel()
    s = np.arange(a*b)
    for fiber in Fibers:
        t.append(fiber.D*fiber.yind + fiber.xind)
    t = np.hstack(t)
    t = np.array(t, dtype=int)
    ind = np.setdiff1d(s,t)
    mask = np.zeros((a*b))
    mask[ind] = 1.
    mask[ind] = 1.-is_outlier(image[ind])
    sel = np.where(mask==1.)[0]
    for i in xrange(niter):
        V = polyvander2d(xgrid[sel],ygrid[sel],[order,order])
        sol = np.linalg.lstsq(V, image[sel])[0]
        vals = np.dot(V,sol) - image[sel]
        sel = sel[~is_outlier(vals)]
    V = polyvander2d(xgrid,ygrid,[order,order])
    back = np.dot(V, sol).reshape(a,b)    
    return back