Method for recording printing forms

A method for picture-element-by-picture-element and picture-line-by-picture-line recording of a printing form, comprising steps of:

• acquiring a picture signal sequence by opto-electronic scanning of a stroke original having stroke elements, said picture signal sequence having picture signal values which are a measure for density values of the scanned stroke original;
• from the acquired picture signal sequence, deriving a signal sequence which contains picture signal values of the acquired picture signal sequence when said picture signal values represent density values of stroke elements to be recorded, and which contains a mask signal value which replaces the picture signal values when such picture signal values represent a prescribable density range of a ground of the original which is not to be recorded and thus defining a mask region, a value of the mask signal value lying outside of a desired value range for the picture signal values;
• allocating to every picture signal value which can occur in the derived signal sequence a recording signal value based on the picture signal value allocated to it, and allocating to the mask signal value an independent recording signal value;
• and
• during recording, employing the picture signal values of the derived signal sequence to call in the allocated recording signal values so as to create a recording signal sequence for controlling a recording element for the printing form.

A system for picture-element-by-picture-element and picture-line-by-picture-line recording of a printing form, a surface of the printing form being divided into sub-areas to be recorded, comprising:

• means for acquiring at least two picture signal sequences each having picture signal values corresponding to picture elements;
• means for deriving for each acquired picture signal sequence a signal sequence containing picture signal values for picture elements lying within at least one sub-area, and for picture elements lying outside of the sub-area, for replacing picture signal values of the respective acquired signal sequence by a mask signal value;
• means for combining the at least two derived signal sequences to form a resulting signal sequence formed of combinations of the signal values to form signal value combinations;
• means for allocating a recording signal value to every picture signal value combination that may occur in the resulting signal sequence;
• and
• means for employing during recording the picture signal value combinations of the resulting signal sequence to call in respective allocated recording signal values to create a recording signal sequence for controlling a recording element for the printing form.

A system for picture-element-by-picture-element and picture-line-by-picture-line recording of a printing form, comprising:

• means for acquiring a picture signal sequence by opto-electronic scanning of a stroke original having stroke elements, said picture signal sequence having picture signal values which are a measure for density values of the scanned stroke original;
• means for deriving from the acquired picture signal sequence, a signal sequence which contains picture signal values of the acquired picture signal sequence when said picture signal values represent density values of stroke elements to be recorded, and which contains a mask signal value which replaces the picture signal values when such picture signal values represent a prescribable density range of a ground of the original which is not to be recorded, thus defining a mask region, a value of the mask signal value lying outside of a desired value range for the picture signal values;
• means for allocating to every picture signal value which can occur in the derived signal sequence with a recording signal value dependent on the picture signal value allocated to it, and for allocating to the mask signal value an independent recording signal value;
• and
• means for employing during recording the picture signal values of the derived signal sequence to call in the allocated recording signal values so as to create a recording signal sequence for controlling a recording element for the printing form.

A system for picture-element-by-picture-element and picture-line-by-picture-line recording of printing forms, comprising:

• at least first and second signal source means for respective acquisition of first and second picture signal sequences;
• first and second controller means respectively connected to the first and second signal source means for calling in the respective picture signal sequences from the first and second signal source means;
• first and second gradation stages respectively connected to the first and second signal source means;
• a signal processing means connected to the first and second gradation stages for formation of a recording signal sequence;
• a printing form recording element connected to the signal processing means;
• and
• said signal processing means including
• first and second mask stage means respectively connected to the first and second gradation stages for formation of signal sequences with signal value combinations from the picture signal sequences,
• first and second allocation controller means respectively connected to the first and second mask stage means for control of the respective mask stage means for generation of said signal value combinations, and
• combining stage means connected to the first and second mask stage means for allocation of recording signal values to said signal value combinations of the signal sequences.