A method of using a charged particle microscope (M) comprising: - A source , for producing a beam (B) of charged particles; - A specimen holder (H), for holding a specimen (S); - An illuminator , for irradiating said specimen with said charged particles; - A detector , for detecting radiation emanating from the specimen (S) in response to said irradiation; - A controller , for controlling at least some aspects of the microscope's (M) operation, which method comprises the steps of: - Using said detector to acquire a successive series of component images {I1,..., In,..., IN} of a given part of the specimen; - Combining said component images so as to assemble a composite image, characterized by the following steps, executed prior to said combining step: - Successively quantizing each component image, and storing it in a memory; - Wherein said successively quantizing each component image comprises: - Recording a quantization error per pixel for each quantized component image, and keeping a running tally Tn of cumulative quantization error per pixel for quantized component images {I1,..., In}; - When quantizing a next component image I n+1 , for a given pixel, choosing a quantization polarity that will tend to avoid further increasing Tn+1 relative to Tn, such that: ▪ If Tn is positive, then Tn+1 will be a smaller positive value, zero, or a negative value; ▪ If Tn is negative, then Tn+1 will be a smaller negative value, zero, or a positive value; ▪ If Tn is zero, then Tn+1 is allowed to be positive, negative or zero. - A source , for producing a beam (B) of charged particles; - A specimen holder (H), for holding a specimen (S); - An illuminator , for irradiating said specimen with said charged particles; - A detector , for detecting radiation emanating from the specimen (S) in response to said irradiation; - A controller , for controlling at least some aspects of the microscope's (M) operation, - Using said detector to acquire a successive series of component images {I1,..., In,..., IN} of a given part of the specimen; - Combining said component images so as to assemble a composite image, characterized by the following steps, executed prior to said combining step: - Successively quantizing each component image, and storing it in a memory; - Wherein said successively quantizing each component image comprises: - Recording a quantization error per pixel for each quantized component image, and keeping a running tally Tn of cumulative quantization error per pixel for quantized component images {I1,..., In}; - When quantizing a next component image I n+1 , for a given pixel, choosing a quantization polarity that will tend to avoid further increasing Tn+1 relative to Tn, such that: ▪ If Tn is positive, then Tn+1 will be a smaller positive value, zero, or a negative value; ▪ If Tn is negative, then Tn+1 will be a smaller negative value, zero, or a positive value; ▪ If Tn is zero, then Tn+1 is allowed to be positive, negative or zero. ▪ If Tn is positive, then Tn+1 will be a smaller positive value, zero, or a negative value; ▪ If Tn is negative, then Tn+1 will be a smaller negative value, zero, or a positive value; ▪ If Tn is zero, then Tn+1 is allowed to be positive, negative or zero. <EOS>