| 摘要 |
PURPOSE:To ensure the averaging for the picture density value without lowering the space resolution when the reverse projection picture from the reverse projection value, by providing the data storage part, the data rearrangement circuit part and the arithmetic circuit part respectively. CONSTITUTION:The reverse projection value averaging device consists of data storage part 10, data rearrangement circuit part 20 and arithmetic circuit part 30 respectively. Six pairs of projection coordinates value x and reverse projection value f under j=1 are supplied in sequence into data line 40 and 41 along the direction of arrow i of the grid (A) to which value x and f are already obtained, and then j=2, 3 ... 6 are followed. At storage part 10, four pairs (x0, f0)-(x3, f3) of value x and f of four grid points which are adjacent each other in diagram (A) are delivered to data lines 60-63 plus 50-53 respectively. At circuit part 20, value x supplied to lines 60-63 are delivered to data lines 80-83 respectively in the order of smaller amount as projection coordinates value x0'-x3'. In the same way, value f data 50-53 are delivered to data lines 70-73 in the form of f0'-f3'. |
