diff --git a/src/image/filter/median.cpp b/src/image/filter/median.cpp index 3c1d4c26..917b8f18 100644 --- a/src/image/filter/median.cpp +++ b/src/image/filter/median.cpp @@ -126,7 +126,91 @@ Image Image::Median(ivec2 ksize) const for (int j = 0; j < lsize.y; ++j) for (int i = 0; i < lsize.x; ++i) { - float d = 1.0f / (1e-10f + distance(median, list[i][j])); + float d = 1.0f / + (1e-10f + distance(median, list[i][j])); + s1 += list[i][j] * d; + s2 += d; + } + median = s1 / s2; + + if (iter > 1 && iter < N) + { + median += K * (median - oldmed); + } + + if (iter > 3 && distance(oldmed, median) < 1.e-5f) + break; + } + + /* Store the median value */ + dstp[y * size.x + x] = vec4(median, srcp[y * size.x + x].a); + } + } + + tmp.Unlock(srcp); + ret.Unlock(dstp); + } + + return ret; +} + +Image Image::Median(Array2D const &kernel) const +{ + ivec2 const size = GetSize(); + Image tmp = *this; + Image ret(size); + + /* FIXME: TODO */ +#if 0 + if (GetFormat() == PixelFormat::Y_8 || GetFormat() == PixelFormat::Y_F32) + { + } + else +#endif + { + ivec2 const ksize = kernel.GetSize(); + Array2D list(ksize); + + vec4 *srcp = tmp.Lock(); + vec4 *dstp = ret.Lock(); + + for (int y = 0; y < size.y; y++) + { + for (int x = 0; x < size.x; x++) + { + /* Make a list of neighbours */ + for (int j = 0; j < ksize.y; j++) + { + int y2 = y + j - ksize.y / 2; + if (y2 < 0) y2 = size.y - 1 - ((-y2 - 1) % size.y); + else if (y2 > 0) y2 = y2 % size.y; + + for (int i = 0; i < ksize.x; i++) + { + int x2 = x + i - ksize.x / 2; + if (x2 < 0) x2 = size.x - 1 - ((-x2 - 1) % size.x); + else if (x2 > 0) x2 = x2 % size.x; + + list[i][j] = srcp[y2 * size.x + x2].rgb; + } + } + + /* Algorithm constants, empirically chosen */ + int const N = 5; + float const K = 1.5f; + + /* Iterate using Weiszfeld’s algorithm */ + vec3 oldmed(0.f), median(0.f); + for (int iter = 0; ; ++iter) + { + oldmed = median; + vec3 s1(0.f); + float s2 = 0.f; + for (int j = 0; j < ksize.y; ++j) + for (int i = 0; i < ksize.x; ++i) + { + float d = kernel[i][j] / + (1e-10f + distance(median, list[i][j])); s1 += list[i][j] * d; s2 += d; } diff --git a/src/lol/image/image.h b/src/lol/image/image.h index 9f7253e8..5e43f6eb 100644 --- a/src/lol/image/image.h +++ b/src/lol/image/image.h @@ -108,6 +108,7 @@ public: Image Convolution(Array2D const &kernel); Image Crop(ibox2 box) const; Image Median(ivec2 radii) const; + Image Median(Array2D const &kernel) const; Image YUVToRGB() const; Image RGBToYUV() const;