In this paper, we propose a single-pass adaptive tokenizer, KARL, which performs variable-length tokenization according to the complexity of an image based on the principles of Algorithmic Information Theory (AIT). KARL uses a learning process similar to the inverse reinforcement learning paradigm by approximating the Kolmogorov complexity (KC) and stopping token generation when the minimum description length is reached. Unlike conventional adaptive tokenizers that require multiple encoding searches, KARL achieves the same performance in a single pass. In addition, we analyze the scaling law for factors such as encoder/decoder size, continuous/discrete tokenization, etc., and explore the relationship between image complexity (KC) and structure/noise, and in/out of distribution familiarity through a conceptual study between adaptive image tokenization and AIT, showing its consistency with human intuition.