naive random scan method of cbir systems

Question

hi iam doing content based image retreival project, in this project 

Iam Following the naive random scan method

in which i have to search the database for a target image

S is total space in database

k is no of datapoints to be retrieved

sk is the the query reslut set

First step: i retrive k datapoints from database

 and serches for the target image

if target image not found

i have to do  s-sk

and then i have to retrieve aging k points

then if traget found display else

do s-sk

and then serch in remaining space this goes on untill the taget image found

so please help me on this

on writing queris to retrive sk

and to do s-sk

THE BREIVE EXPLANATION FOR ABOVE METHOD

NAIVE RANDOM SCAN METHOD

INPUT:

set of images                               -s

number of retreived images at each iteration- k

OUTPUT

target image pt

01-> qs(sample query for s)

02-> sk (EVALUATE QUERY) randomly retrieve k points is S

03-> S1 <-s=sk

while user does not find pt?(target point) in sk do

04->Qr <-next query for s1

05<- Sk (evaluate query) randomly retrive k points is s1(s1=s-sk)

06<- s1=s1-k

end do

return pt