The invention relates to a process and device for scanning cells of a matrix-controlled display for the displaying of grey levels of a video signal, the scan being split up into sub-scans relating to each bit of column control words, characterized in that, when the coding of image does not activate the high-order bit, the processing sub-scan relating to this bit is allocated to the displaying of an additional item which corresponds to a bit of lower weight than the smallest weight of the column control word used when the condition is not fulfilled. The applications of the invention relate to matrix-controlled display devices using the principle of temporal modulation for the generation of halftones, especially plasma panels of the a.c. type with memory or d.c. type with memory.