System for scanning recycled paper before printing

A computer program product for printing to a paper sheet, comprising machine-readable code for causing a machine to perform the method steps of:

• scanning the paper sheet for at least zero existing marks;
• comparing an intended output and the at least zero existing marks to detect an overlap between the intended output and the at least zero existing marks;
• printing the intended output to the paper sheet upon determining the suitability of printing the intended output to the paper sheet,
• wherein comparing of an intended output and the at least zero existing marks comprises determining printing the intended output to the paper sheet suitable if a degree of overlap between the intended output and the at least zero existing marks is less than the user-customizable, threshold overlap value;
• and wherein comparing of an intended output and the at least zero existing marks comprises determining printing the intended output to the paper sheet suitable if a detected separation distance between the intended output and the at least zero existing marks is greater than the user-customizable, threshold separation-distance value, wherein the detected separation distance is detected by estimating the separation distance between a low-resolution image of the intended output and a low-resolution image of the at least zero existing marks.

A computing system comprising a print engine, programmed to print to a paper sheet, comprising:

• scanning the paper sheet for at least zero existing marks;
• comparing an intended output and the at least zero existing marks to detect an overlap between the intended output and the at least zero existing marks;
• printing the intended output to the paper sheet upon determining the suitability of printing the intended output to the paper sheet,
• wherein comparing of an intended output and the at least zero existing marks comprises determining printing the intended output to the paper sheet suitable if a degree of overlap between the intended output and the at least zero existing marks is less than the user-customizable, threshold overlap value and wherein comparing of an intended output and the at least zero existing marks comprises determining printing the intended output to the paper sheet suitable if a detected separation distance between the intended output and the at least zero existing marks is greater than the user-customizable, threshold separation-distance value, wherein the detected separation distance is detected by estimating the separation distance between a low-resolution image of the intended output and a low-resolution image of the at least zero existing marks.