$\star$ Charts of weight

We thus have now the chart of possible the artifacts, they will be put in veto during the construction of the major images. As the weights of the images now will vary pixel with pixel, simplest is of the encoder in an image:

$$w_{i,j} = \frac{flat^2_{i,j}} {Var_{ciel}}$$ (7.21)

in which the died pixels, containing the cosmic ones or satellites are put at zero. Figure 7.16 presents an example of chart of weight.

We lay out now of all the ingredients to build an optimal major image and without artifacts.

Figure 7.16: This figure presents part of the chart of weight of an image taken in the filter R with MegaCam in June 2003. At left a detail of the image corrected for the quantum effectiveness with withdrawn bottom is presented, on the right its chart of weight. In particular, we see that the dead column (the vertical line in the image), the satellite (the oblique line) and the pixels containing of cosmic (surrounded in white on the image and black on the chart of weight) are put at zero in the chart of weight.