Traditionally, population balance (PB) modeling of crystal growth in crystallizers has been based on a single scalar parameter for particle size, typically the volume equivalent diameter. This misses important information about particle shape, especially for crystals of high aspect ratios. In recent years attempts have been made to extend PB to two or more size dimensions by taking into consideration of the crystal shape. A key step in multi-dimensional PB (M-PB) modeling is the estimation of the growth rates of individual faces as a function of temporal operating conditions, e.g. the supersaturation. In this paper, we propose to carry out M-PB modeling based on real-time experimentally derived growth rates for different faces using in-process imaging and image analysis. Results are presented for the seeded cooling crystallisation of rod-like beta-form L-glutamic acid in a 0.5-1 batch reactor.