Project raised exception class EAccess Violation in BCB 6.0

Project raised exception class EAccess Violation in BCB 6.0

My code can compile successfully and run, however when I terminate it, the
error message appears occasionally.
Project raised exception class EAccess Violation with message 'Access
violation at address 0040..... in module `00F.....`. Write of address
..........' Process stopped. Use step or Run to continue.
and I also noticed that the error always happens within these three lines
of code in turn.
YCB[i][j].R=((65.738*image[i][j].R)+(129.057*image[i][j].G)+(25.064*image[i][j].B))/256+16;
YCB[i][j].G=((-37.945*image[i][j].R)+(-74.494*image[i][j].G)+(112.439*image[i][j].B))/256+128;
YCB[i][j].B=((112.439*image[i][j].R)+(-94.154*image[i][j].G)+(-18.285*image[i][j].B))/256+128;
The code is used to transfer RGB to YCbCr
because my program has a function that records the screen into .avi file,
as long as the error appears when I terminate it, the file cannot store
perfectly (which means it cannot open by any means of player).
This question troubles me, though sometimes nothing occurs...
I really want to understand what this message means, and how can I solve
it when it shows up again.
P.S Seems like it has something to do with the memory, how can I inspect
the memory record in BCB 6.0 ??