operation of the “image” and “pcolor” function in matlab for visualizing matrices

Question

I have matrices which I wish to visualize to get a feel for the values they contain. But the function image which I use by default gives a poor result. I have to scale the matrix manually with an appropriate value before the visualization is suitable. my matrices scaled by value 1:

image(Breceive(1+(ii-1)*20:20+(ii-1)*20,:)*1)

my matrices scaled by value 10

image(Breceive(1+(ii-1)*20:20+(ii-1)*20,:)*10)

my matrices scaled by value 50

image(Breceive(1+(ii-1)*20:20+(ii-1)*20,:)*50)

my matrices scaled by value 10000

image(Breceive(1+(ii-1)*20:20+(ii-1)*20,:)*10000)

my matrices with value 10000 added

image(Breceive(1+(ii-1)*20:20+(ii-1)*20,:)+10000)

but using function pcolor the scaling or addition does not change the presented matrices' colorings regardless of the value But actually we see that a different number of rows get colored (6 here but 7 before)

pcolor(Breceive(1+(ii-1)*20:20+(ii-1)*20,:))

I thought that image should be scale invariant? That it normalizes the data beforehand. Can pcolor be trusted that it is doing a proper scale translation to color values? Is there some parameter or way to make image be stable? And why is pcolor not plotting the same information?