An image sensor , comprising: a matrix of rows and columns of photosensitive pixels , wherein the matrix comprises a plurality of stitching blocks that are adjacently arranged in the column direction of the matrix; wherein each stitching block comprises: a plurality of first pixels and a plurality of second pixels ; a plurality of dose select lines configured for carrying respective dose select signals; and a pixel select controller configured for: in an image read-out mode of the image sensor, simultaneously selecting first pixels and second pixels , in a given row and given stitching block, one row at a time; in a dose sensing mode of the image sensor , simultaneously selecting second pixels in different rows and different stitching blocks in dependence of the dose select signals; the image sensor further comprising, at each connecting interface between stitching blocks that are adjacently arranged in the column direction, a dose select line connecting unit for connecting each dose select line of a first stitching block among the adjacent stitching blocks to a respective dose select line of a second stitching block among the adjacent stitching blocks to prevent multiple second pixels in the same column of the matrix from being selected. a matrix of rows and columns of photosensitive pixels , wherein the matrix comprises a plurality of stitching blocks that are adjacently arranged in the column direction of the matrix; wherein each stitching block comprises: a plurality of first pixels and a plurality of second pixels ; a plurality of dose select lines configured for carrying respective dose select signals; and a pixel select controller configured for: in an image read-out mode of the image sensor, simultaneously selecting first pixels and second pixels , in a given row and given stitching block, one row at a time; in a dose sensing mode of the image sensor , simultaneously selecting second pixels in different rows and different stitching blocks in dependence of the dose select signals; a plurality of first pixels and a plurality of second pixels ; a plurality of dose select lines configured for carrying respective dose select signals; and a pixel select controller configured for: in an image read-out mode of the image sensor, simultaneously selecting first pixels and second pixels , in a given row and given stitching block, one row at a time; in a dose sensing mode of the image sensor , simultaneously selecting second pixels in different rows and different stitching blocks in dependence of the dose select signals; in an image read-out mode of the image sensor, simultaneously selecting first pixels and second pixels , in a given row and given stitching block, one row at a time; in a dose sensing mode of the image sensor , simultaneously selecting second pixels in different rows and different stitching blocks in dependence of the dose select signals; the image sensor further comprising, at each connecting interface between stitching blocks that are adjacently arranged in the column direction, a dose select line connecting unit for connecting each dose select line of a first stitching block among the adjacent stitching blocks to a respective dose select line of a second stitching block among the adjacent stitching blocks to prevent multiple second pixels in the same column of the matrix from being selected. <EOS>