[求助]请问一下 这面这段语句是什么意思哈？（急！）

[xwleon]

DBlocksReduce(k1,:,:)=Image4((i1-1)*Sr+1:i1*Sr,(j1-1)*Sr+1:j1*Sr);
switch l1-1
case 0
DBlocksReduce(l,:,:)=Image4((i1-1)*Sr+1:i1*Sr,(j1-1)*Sr+1:j1*Sr);
case 1
DBlocksReduce(l,:,:)=DBlocksReduce(k1,m:-1:1,:);
case 2
DBlocksReduce(l,:,:)=DBlocksReduce(k1,:,n:-1:1);
case 3
DBlocksReduce(l,:,:)=DBlocksReduce(k1,m:-1:1,n:-1:1);
case 4
DBlocksReduce(l,:,:)=reshape(DBlocksReduce(k1,:,:),Sr,Sr)';
case 5
DBlocksReduce(k1+3*Dnum,:,:)=DBlocksReduce(k1,m:-1:1,n:-1:1);
A=reshape( DBlocksReduce(k1+3*Dnum,:,:),Sr,Sr)';
DBlocksReduce(l,:,:)=A(:,n:-1:1);
case 6
DBlocksReduce(l,:,:)=imrotate(reshape(DBlocksReduce(k1,:,:),Sr,Sr),90);
case 7
DBlocksReduce(l,:,:)=imrotate(reshape(DBlocksReduce(k1,:,:),Sr,Sr),270);
end
RBlocks(k,:,:)=RandDbesta(k)*DBlocksReduce(l,:,:)+RandDbestb(k);
Image3((i-1)*Sr+1:i*Sr,(j-1)*Sr+1:j*Sr)=reshape(RBlocks(k,:,:),Sr,Sr);
end
end

end