Getting grey level value

[Enriquez]

Hi Everyone!

How am I going to get the value of grey level of each pixel from the bmp file in a look up table?, I already got my phase value so its just the grey level that i have to get.

The attachment is what i have done.

Greatly appreciate anyones help:)

[ABCPrograms]

If you have the same problem you might want to stick with the same post

http://forums.ni.com/t5/LabVIEW/Calculating-phase/m-p/2418936#M746679

[alexderjuengere]

Hi again Enriquez,

I assume you want your look-up-table to be in u8 as there are only 256 greyscales to be.

Your input is u32 = 2^32 =256^4

Your desired output is u8 = 2^8 = 256^1

You could divide your input u32 array 3 times through 256 e.g. using a FOR loop, or you could cube root the u32 array directly, or use the "split number.vi" three times sequentially.

[Enriquez]

Hi alex!

I have made changes in my program, instead of getting my grey level according to my bmp file, i made a constant to make my lens bmp file.

I have attached my vi:)

Thanks a lot!

[alexderjuengere]

Hi Enriquez,

I guess I misunderstood your intention;

now I think I understand what you want to do:

Alex

[Enriquez]

Here I've attached my VI

[alexderjuengere]

Hi Enriquez,

wow, this is quite ... creative.

Obviously, you want to plot "phase" as a function of "grey level" e.g. y_phase value = f(x_greylevel).

For which row or column of the phase array and the corresponding greylevel array?

Maybe, for all rows/columns?

Alex

[Enriquez]

Hi,

 I actually want all the rows of phase array corresponding to grey level array shown in the graph.

Thanks! 

[alexderjuengere]

I think you're looking for somekind of distribution function

1# re-shape the 2d Arrays to 1d Arrays

So, if your 2d array has 50 rows x 50 columns your reshaped 1d array is supposed to have 1 row and 50*50=2500 columns

2# Build an 1d array of clusters with each cluster-element containing 1 greyscale and 1 phase value

Important: the greyscale array is to be the first cluster element!

3# Sort this 1d array of cluster with the "sort 1d array.vi";

this vi uses a stable sorting algorithm which maintains the relative order of phase values with equal greyscales

4# On the Frontpanel, change the greyscale indicator element in the 1d array of cluster element to a color constant

Now, you will have redundant values in the sorted 1d array of clusters which has the dimension 1 row x 2500 columns;

redundant values are indicated for example when i - (i+1) = 0 is TRUE.