diff --git a/src/ipa/libipa/histogram.cpp b/src/ipa/libipa/histogram.cpp
index c1aac59b..628e3755 100644
--- a/src/ipa/libipa/histogram.cpp
+++ b/src/ipa/libipa/histogram.cpp
@@ -40,14 +40,8 @@ namespace ipa {
 /**
  * \brief Create a cumulative histogram
  * \param[in] data A pre-sorted histogram to be passed
+ * \param[in] transform The transformation function to apply to every bin
  */
-Histogram::Histogram(Span<const uint32_t> data)
-{
-	cumulative_.reserve(data.size());
-	cumulative_.push_back(0);
-	for (const uint32_t &value : data)
-		cumulative_.push_back(cumulative_.back() + value);
-}
 
 /**
  * \fn Histogram::bins()
diff --git a/src/ipa/libipa/histogram.h b/src/ipa/libipa/histogram.h
index 54bb2a19..26326125 100644
--- a/src/ipa/libipa/histogram.h
+++ b/src/ipa/libipa/histogram.h
@@ -10,10 +10,10 @@
 #include <assert.h>
 #include <limits.h>
 #include <stdint.h>
-
 #include <vector>
 
 #include <libcamera/base/span.h>
+#include <libcamera/base/utils.h>
 
 namespace libcamera {
 
@@ -23,7 +23,17 @@ class Histogram
 {
 public:
 	Histogram() { cumulative_.push_back(0); }
-	Histogram(Span<const uint32_t> data);
+
+	template<typename Transform>
+	Histogram(Span<const uint32_t> data,
+		  Transform transform = [](uint32_t x) { return x; })
+	{
+		cumulative_.resize(data.size() + 1);
+		cumulative_[0] = 0;
+		for (const auto &[i, value] : utils::enumerate(data))
+			cumulative_[i + 1] = cumulative_[i] + transform(value);
+	}
+
 	size_t bins() const { return cumulative_.size() - 1; }
 	uint64_t total() const { return cumulative_[cumulative_.size() - 1]; }
 	uint64_t cumulativeFrequency(double bin) const;