Padding issue

[hcfugro]

I'm trying to get gradient of an image matrix
Images v0.26.1
Julia Version 1.10.4

`using Images
#morph_image size is 301x301
sobel_x_kernel = [[-0.125, 0.0, 0.125]; [0.0, 0.0, 0.0]; [-0.125, 0.0, 0.125]]
sobel_y_kernel = transpose(sobel_x_kernel) # Transpose for y-direction

pad_size = 1 # Adjust pad size if needed

padded_image = Images.pad(morph_image, pad_size, pad_size)
gradient_x = imfilter(padded_image, sobel_x_kernel)
gradient_y = imfilter(padded_image, sobel_y_kernel) # Works without an issue
`

Here's a breakdown of the problem:

Expected behavior: When I apply padding or a background gradient to an image, the padding should create a space around the image content and the gradient should fill that space.
Actual behavior: Image remains the same size

Things I've tried:

I've verified that the padding and gradient styles are being applied to the correct element and that  image has a defined height and width.

M is 5x5 window of morph_image
julia> M

5×5 Matrix{Float64}:
1.0 11.0 11.0 11.0 11.0
1.0 11.0 11.0 11.0 11.0
1.0 11.0 11.0 11.0 11.0
1.0 1.0 11.0 11.0 11.0
1.0 1.0 1.0 1.0 11.0

julia> gradient_y = imfilter(M, sobel_y_kernel)

5×5 Matrix{Float64}:
0.0 0.0 0.0 1.25 1.25
0.0 0.0 0.0 1.25 1.25
0.0 0.0 0.0 1.25 1.25
0.0 0.0 0.0 0.0 1.25
1.25 1.25 0.0 0.0 0.0

julia> gradient_x = imfilter(M, sobel_x_kernel)

ERROR: ArgumentError: Pad{1}(:replicate, (4,), (4,)) lacks the proper padding sizes for an array with 2 dimensions
Stacktrace:
[1] BorderArray(inner::Matrix{Float64}, border::Pad{1})
@ ImageFiltering ~/.julia/packages/ImageFiltering/OyzRu/src/borderarray.jl:64
[2] padarray(::Type{Float64}, img::Matrix{Float64}, border::Pad{1})
@ ImageFiltering ~/.julia/packages/ImageFiltering/OyzRu/src/border.jl:326
[3] imfilter!(r::ComputationalResources.CPU1{…}, out::Matrix{…}, img::Matrix{…}, kernel::Tuple{…}, border::Pad{…})
@ ImageFiltering ~/.julia/packages/ImageFiltering/OyzRu/src/imfilter.jl:336
[4] imfilter!(r::ComputationalResources.CPU1{…}, out::Matrix{…}, img::Matrix{…}, kernel::Tuple{…}, border::Pad{…})
@ ImageFiltering ~/.julia/packages/ImageFiltering/OyzRu/src/imfilter.jl:327
[5] imfilter!(out::Matrix{…}, img::Matrix{…}, kernel::Tuple{…}, border::Pad{…}, alg::ImageFiltering.Algorithm.FIR)
@ ImageFiltering ~/.julia/packages/ImageFiltering/OyzRu/src/imfilter.jl:236
[6] imfilter!(out::Matrix{Float64}, img::Matrix{Float64}, kernel::Tuple{OffsetArrays.OffsetVector{Float64, Vector{Float64}}}, border::Pad{0})
@ ImageFiltering ~/.julia/packages/ImageFiltering/OyzRu/src/imfilter.jl:230
[7] imfilter
@ ~/.julia/packages/ImageFiltering/OyzRu/src/imfilter.jl:25 [inlined]
[8] imfilter(::Type{Float64}, ::Matrix{Float64}, ::Tuple{OffsetArrays.OffsetVector{Float64, Vector{Float64}}}, ::String)
@ ImageFiltering ~/.julia/packages/ImageFiltering/OyzRu/src/imfilter.jl:20
[9] imfilter(::Type{Float64}, ::Matrix{Float64}, ::Tuple{OffsetArrays.OffsetVector{Float64, Vector{Float64}}})
@ ImageFiltering ~/.julia/packages/ImageFiltering/OyzRu/src/imfilter.jl:16
[10] imfilter
@ ~/.julia/packages/ImageFiltering/OyzRu/src/imfilter.jl:8 [inlined]
[11] imfilter(::Matrix{Float64}, ::Vector{Float64})
@ ImageFiltering ~/.julia/packages/ImageFiltering/OyzRu/src/imfilter.jl:3
[12] top-level scope
@ REPL[314]:1

I also tried this:

SO I tried reflect but the test and reflected images They have the same size
test_image = rand(5, 5)  # Create a small test image
reflected_test_image = reflect(test_image)
println(size(test_image))
println(size(reflected_test_image))

Has anyone else experienced this issue? Any suggestions on how to troubleshoot or fix this would be greatly appreciated.

[kimikage]

sobel_x_kernel is not a Matrix.

julia> sobel_x_kernel = [[-0.125, 0.0, 0.125]; [0.0, 0.0, 0.0]; [-0.125, 0.0, 0.125]]
9-element Vector{Float64}:
 -0.125
  0.0
  0.125
  0.0
  0.0
  0.0
 -0.125
  0.0
  0.125

Did you mean:

julia> [-0.125 0.0 0.125; 0.0 0.0 0.0; -0.125 0.0 0.125]
3×3 Matrix{Float64}:
 -0.125  0.0  0.125
  0.0    0.0  0.0
 -0.125  0.0  0.125