Mercurial > repos > ImageTools / file comparison
comparison: src/ImFilter.jl
src/ImFilter.jl
- changeset 18
- 0d99f8f7d261
- child 22
- 4403f0445814
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| 17:8ff7da7bc77d | 18:0d99f8f7d261 |
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| 1 ################################################## | |
| 2 # Simple (and fast for small filters compared to | |
| 3 # ImageFiltering) image filtering | |
| 4 ################################################## | |
| 5 | |
| 6 __precompile__() | |
| 7 | |
| 8 module ImFilter | |
| 9 | |
| 10 using OffsetArrays | |
| 11 | |
| 12 ########## | |
| 13 # Exports | |
| 14 ########## | |
| 15 | |
| 16 export simple_imfilter | |
| 17 | |
| 18 ############## | |
| 19 # The routine | |
| 20 ############## | |
| 21 | |
| 22 @inline function inside(i, aʹ, bʹ, a, b) | |
| 23 return (max(a, i - aʹ) - i):(min(b, i + bʹ) - i) | |
| 24 end | |
| 25 | |
| 26 function simple_imfilter(b::Array{Float64,2}, | |
| 27 kernel::OffsetArray{Float64,2,Array{Float64,2}}) | |
| 28 | |
| 29 n, m = size(b) | |
| 30 k, 𝓁 = size(kernel) | |
| 31 o₁, o₂ = kernel.offsets | |
| 32 a₁, a₂ = k + o₁, 𝓁 + o₂ | |
| 33 b₁, b₂ = -1 - o₁, -1 - o₂ | |
| 34 kp = kernel.parent | |
| 35 | |
| 36 @assert(isodd(k) && isodd(𝓁)) | |
| 37 | |
| 38 res = similar(b) | |
| 39 | |
| 40 Threads.@threads for i=1:n | |
| 41 for j=1:m | |
| 42 tmp = 0.0 | |
| 43 it₁ = inside(i, a₁, b₁, 1, n) | |
| 44 it₂ = inside(j, a₂, b₂, 1, m) | |
| 45 for p=it₁ | |
| 46 @simd for q=it₂ | |
| 47 tmp += @inbounds(kp[p-o₁, q-o₂]*b[i+p,j+q]) | |
| 48 end | |
| 49 end | |
| 50 res[i, j] = tmp | |
| 51 end | |
| 52 end | |
| 53 | |
| 54 return res | |
| 55 end | |
| 56 | |
| 57 end # Module | |
| 58 |
