Given the following context:

The Rokeby Venus is the only surviving nude by Velázquez, but three others by the artist are recorded in 17th-century Spanish inventories. Two were mentioned in the Royal collection, but may have been lost in the 1734 fire that destroyed the main Royal Palace of Madrid. A further one was recorded in the collection of Domingo Guerra Coronel. These records mention "a reclining Venus", Venus and Adonis, and a Psyche and Cupid.Although the work is widely thought to have been painted from life, the identity of the model is subject to much speculation. In contemporary Spain it was acceptable for artists to employ male nude models for studies; however, the use of female nude models was frowned upon. The painting is believed to have been executed during one of Velázquez's visits to Rome, and Prater has observed that in Rome the artist "did indeed lead a life of considerable personal liberty that would have been consistent with the notion of using a live nude female model". It has been claimed that the painting depicts a mistress Velázquez is known to have had while in Italy, who is supposed to have borne his child. Others have claimed that the model is the same as in Coronation of the Virgin and Las Hilanderas, both in the Museo del Prado, and other works.The figures of both Venus and Cupid were significantly altered during the painting process, the result of the artist's corrections to the contours as initially painted. Pentimenti can be seen in Venus's upraised arm, in the position of her left shoulder, and on her head. Infra-red reveals that she was originally shown more upright with her head turned to the left. An area on the left of the painting, extending from Venus's left foot to the left leg and foot of Cupid, is apparently unfinished, but this feature is seen in many other works by Velázquez and was probably deliberate. The painting was given a major cleaning and restoration in 1965–66, which showed it to be in good condition, and with very little paint added later by other artists, contrary to what some...

answer the following question:

What is the name of the artist whose corrections to the contours as initially painted resulted in the figures of both Venus and Cupid being significantly altered during the painting process? 

Velázquez