28 lines
891 B
Common Lisp
28 lines
891 B
Common Lisp
;; Threshold effect using xector operations
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;; Demonstrates where (conditional select) and β (reduction) for normalization
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(require-primitives "xector")
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(define-effect xector_threshold
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:params (
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(threshold :type float :default 0.5 :range [0 1] :desc "Brightness threshold (0-1)")
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(invert :type bool :default false :desc "Invert the threshold")
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)
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(let* (
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;; Get grayscale luminance as xector
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(luma (gray frame))
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;; Normalize to 0-1 range
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(luma-norm (α/ luma 255))
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;; Create boolean mask: pixels above threshold
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(mask (if invert
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(α< luma-norm threshold)
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(α>= luma-norm threshold)))
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;; Use where to select: white (255) if above threshold, black (0) if below
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(out (where mask 255 0)))
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;; Output as grayscale (same value for R, G, B)
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(rgb out out out)))
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