Transformar imagem em byte e depois em String

Bom dia pessoal, tem alguma forma de pegar uma uma imagem em um diretório, transformar em byte e depois em String. Queria que a String ficasse parecida com isso:

iVBORw0KGgoAAAANSUhEUgAAAV4AAAFeCAYAAADNK3caAAAABGdBTUEAALGPC\\/xhBQAAAAlwSFlzAAAOwwAADsMBx2+oZAAA\\/7JJREFUeF7s\\/QV8VtfWtQ+3xd3d3d1dSwsUCoXiWtwp7u6a4O7uLoHgCQ5BI4S4u+EyvmvdIT3tec77P21PT1++97npb\\/e2rWtnjzXWmGPO9YWs\\/6wtYG0BawtYW+C\\/3gIf9EEfP36U3ktf\\/NePZj2AtQWsLWBtAWsLALtW4LX+GVhbwNoC1hb4W1vACrx\\/a3NbD2ZtAWsLWFtAVsZr\\/SOwtoC1Bawt8He3gJXx\\/t0tbj2etQWsLfC\\/vgWswPu\\/\\/k\\/A2gDWFrC2wN\\/dAlbg\\/btb3Ho8awtYW+B\\/fQtYgfd\\/\\/Z+AtQGsLWBtgb+7BazA+3e3uPV41hawtsD\\/+hawAu\\/\\/3\\/0JkO2if7f8vlX+j\\/v5593\\/mzZKWP13NeUf3PdvLvV3HeDPrmRO7J\\/+\\/eZcP31IWO1frP6vj\\/zv7tWvf\\/8D5\\/6bRv9IM\\/36v\\/g7a\\/n3u8\\/zDxzbuup\\/3AJW4P2Pm\\/C\\/uwPLc\\/Obh50cw4\\/v+JIl4dW8T1gs332I34aX\\/+NiyZx5qw8fXv92f2b7j2Z7dvDBpDSa45l131sWiwPxw3v+z2f+e89v71jMqzmc+S5+\\/V8f\\/J86AvOT5TI+6h3Lh0+Hsxw2fieW1w\\/v+f2teeVz\\/Gl8ejXbmPNLWCf+8\\/v3HPfTPiy4ZPZjFnPWn95\\/4AvLYrblu3dsE78G12M50KcNEtrP8hP7NSdi2ubTcT9d7D\\/a+VNzWY7zyy0zH8w2n7ZNeP\\/h1\\/eO32QWc+x\\/nPO\\/7VsTmtdyR97z39tfLfH34pe\\/ASv4\\/ncf0j+xdyvw\\/olG+zs3+R\\/A+wv6fEIj88Balnc8Z28+LeZ9AlIloNqvnmoDEiDPOwDhPWDw4RNQfuS7j+8\\/gcuvgdvA6S\\/AawCY\\/ZsFAPlgtufYCct73htYNt+8sSzvLa\\/.....