<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="d1e356" altimg="si181.svg"> <mml:mi>β</mml:mi> </mml:math> -SGP: Scaled Gradient Projection with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="d1e361" altimg="si181.svg"> <mml:mi>β</mml:mi> </mml:math> -divergence for astronomical image restoration