Is it permissible for a husband to remove a picture of himself with his wife from her family's home without their consent, especially since the picture was taken before his wife committed to wearing the hijab, and he does not wish to see her unveiled?

The questioner has done well in removing this picture. He should try to convince his wife's family of the correctness of his action, due to the Prophet's (peace and blessings be upon him) saying: "Indeed, the angels do not enter a house in which there is a dog or a picture." Furthermore, the picture might be seen by someone to whom it is unlawful to see the woman, and it might cause her harm. There is no sin upon the husband for what he did; rather, his action is required of him.