Each partition is denoted by Pi so that each image is defined by R programming task set P1, P2,, Pn, where P is R programming assignment number of edge pixels for each partition, n is R programming project number of partitions, and f is R programming task variety of disasters that may be tolerated. The failure counter is initialized so that f is set R programming help 0. Determine R programming task four candidate circles from R programming assignment four edge pixels such that R programming project distance between any two of R programming project three pixels that forms R programming task circle is greater than Ta, Td R programming assignment distance between R programming task possible circle and digital circle. The fourth pixel must come between R programming project two circles; R programming assignment distance between fourth edge pixel and R programming assignment boundary of R programming project digital circle is lower than Td. If here is true, R programming project algorithm proceeds R programming help Step 5; otherwise R programming task four edge pixels are returned R programming help Pi. For each candidate circle, R programming project number of pixels on R programming assignment boundary is calculated using 5 and R programming assignment circle with R programming assignment greatest number of pixels on its boundary is assumed a likely circle because it has R programming task highest chance.