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Ensure stats can be calculated for 1x1 input #2372

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Lovell Fuller
2020-09-17 11:08:52 +01:00
parent c3898487c4
commit b369c4bb8a
3 changed files with 24 additions and 6 deletions
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14
src/stats.cc
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@@ -80,12 +80,14 @@ class StatsWorker : public Napi::AsyncWorker {
// Estimate entropy via histogram of greyscale value frequency
baton->entropy = std::abs(greyscale.hist_find().hist_entropy());
// Estimate sharpness via standard deviation of greyscale laplacian
VImage laplacian = VImage::new_matrixv(3, 3,
0.0, 1.0, 0.0,
1.0, -4.0, 1.0,
0.0, 1.0, 0.0);
laplacian.set("scale", 9.0);
baton->sharpness = greyscale.conv(laplacian).deviate();
if (image.width() > 1 || image.height() > 1) {
VImage laplacian = VImage::new_matrixv(3, 3,
0.0, 1.0, 0.0,
1.0, -4.0, 1.0,
0.0, 1.0, 0.0);
laplacian.set("scale", 9.0);
baton->sharpness = greyscale.conv(laplacian).deviate();
}
// Most dominant sRGB colour via 4096-bin 3D histogram
vips::VImage hist = sharp::RemoveAlpha(image)
.colourspace(VIPS_INTERPRETATION_sRGB)