CODEWITHSUNDEEP
image-processingjulia
daycaster
daycaster

Reputation: 2707

How to set a pixel's RGB value

So far I have this:

enter image description here

using Images, Colors
a = Array{UInt8}(5, 5, 3)
imOutput = colorim(a)

How do I assign three values to a pixel:

imOutput[1,1] =

Upvotes: 0

Views: 462

Answers (2)

Felipe Lema
Felipe Lema

Reputation: 2718

I think you meant (mind the dimensions for a)

a = Array{UInt8}(3,5,5)
imOutput = colorim(a)
imOutput[1,1] = RGB(0,0,0)
imOutput

The tests for Images.jl helped me realize this.

Upvotes: 2

Gnimuc
Gnimuc

Reputation: 8566

i didn't know there is a data() function, i actually find the solution by doing dump(imOutput):

Images.Image{FixedPointNumbers.UfixedBase{UInt8,8},3,Array{FixedPointNumbers.UfixedBase{UInt8,8},3}} 
  data: Array(FixedPointNumbers.UfixedBase{UInt8,8},(5,5,3)) 5x5x3 Array{FixedPointNumbers.UfixedBase{UInt8,8},3}:
[:, :, 1] =
 0.314  0.498  0.337  0.0    0.102
 0.584  0.0    0.549  0.565  0.498
 0.337  0.0    0.102  0.212  0.0  
 0.549  0.816  0.498  0.906  0.0  
 0.102  0.584  0.0    0.545  0.188

[:, :, 2] =
 0.588  0.0  0.0  0.0  0.0
 0.337  0.0  0.0  0.0  0.0
 0.549  0.0  0.0  0.0  0.0
 0.102  0.0  0.0  0.0  0.0
 0.498  0.0  0.0  0.0  0.0

[:, :, 3] =
 0.0  0.0  0.0  0.0  0.0
 0.0  0.0  0.0  0.0  0.0
 0.0  0.0  0.0  0.0  0.0
 0.0  0.0  0.0  0.0  0.0
 0.0  0.0  0.0  0.0  0.0
  properties: Dict{ASCIIString,Any} len 3
    colorspace: ASCIIString "RGB"
    colordim: Int64 3
    spatialorder: Array(ASCIIString,(2,)) ASCIIString["y","x"]

the output shows that you can use imOutput.data to access the data. and yes, this is totally the same as data() function, take a look at this line.

from the output, we can see imOutput's colorspace is RGB, so if we have a color from HSL, we should convert that color into RGB space before we pass that color into imOutput.data. for example, 

a = convert(RGB, HSL(270, 0.5, 0.5))
imOutput.data[1,1,:] = [a.r, a.g, a.b]

Upvotes: 1

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