Experimental data, simulation, data analysis and visualisation require image file formats that are open source and able to contain and manage quantitative data. Quantification techniques bring the new challenge of managing image calibration parameters and formulas in an open and efficient format, compatible with routine microscopy workflows. A practical approach to quantitative image format is presented and discussed here, relying on open and extensible file formats - Tagged Image File (TIF) and Extensible Metadata Platform (XMP).