All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The contemporary jurists differed in opinion about the ruling on photographic pictures, and we [in Islamweb] favor the opinion that says that they are permissible. For more benefit, please refer to Fataawa 87005, 83020 and 83249.
However, there are many disadvantages for a woman in taking these pictures, not the least of which is that non-Mahram men could see them. Therefore, it is better for you to completely avoid such pictures. You may just look yourself in the mirror or track your weight loss using a balance.