A problem inherent to radiographic images, which may occur when an independent component analysis technique is applied to energy subtraction carried out on radiographic images, is solved to achieve separation of image components to be separated with higher accuracy. The fiber preform is then kept in its shape by the fibers provided with the interphase coating and is consolidated by being impregnated with a liquid composition containing a ceramic precursor, and by transforming the precursor into a ceramic matrix consolidation phase. The row decoder allows the integration time points of the unit pixels, which are included in the pixel array, to be identical.