Abstract: Image processing method wherein an image is re-sampled and sharpened by subjecting the image to a convolution with a kernel, the elements of which are determined by selecting a first set of kernel values so that a convolution of the image by means of a kernel with said first set of kernel values generates a sharpened image, and subsequently interpolating between the elements of this first kernel.

Abstract: Thermal recording comprising the steps of supplying input data I.sub.u to a processing unit (23) of a printer having a thermal head with a plurality of heating elements; storing input data of a line into a buffer memory (24), further called input line data I.sub.l ; converting (25) the data I.sub.l into serial configurated data I.sub.s ; mapping (32) the data I.sub.s with resistance compensation data into power mapped data I.sub.m ; shifting the data I.sub.m into a shift buffer memory (26), further called shifted power mapped data I.sub.m' ; counting (33) a number N.sub.s,on of simultaneously activated heating elements; adapting (34) a strobe duty cycle .delta. (35) in accordance with N.sub.s,on, further called voltage corrected strobe duty cycle .delta..sub.v ; providing (36) the .delta..sub.v and the data I.sub.m' to the heating elements for reproducing the line of an image.

Abstract: A thermal sublimation printer comprises means for counting at periodic observation times the number (N.sub.h) of activated heating elements; means for measuring at periodic observation times the temperature (T.sub.d) of the drum and the temperature (T.sub.h) of the heatsink; means for digitising the measured temperature of the drum and the measured temperature of the heatsink; means for transferring the number of activated heating elements and the digitised temperature values T.sub.d and T.sub.h ; a device for estimating the temperature (T.sub.e) of the heating elements based on the values of N.sub.h, T.sub.d and T.sub.h ; memory means for storing the estimate of the temperature of the heating elements; the printer operating to adjust the applied energy as a function of the estimate of the temperature of the heating elements and of the required temperature of the heating elements.