Initial code for Sharpen effect.

src/CMakeLists.txt

@@ -119,6 +119,7 @@ set(EFFECTS_SOURCES
   effects/Negate.cpp
   effects/Pixelate.cpp
   effects/Saturation.cpp
+  effects/Sharpen.cpp
   effects/Shift.cpp
   effects/Wave.cpp
   audio_effects/STFT.cpp

src/EffectInfo.cpp

@@ -12,6 +12,7 @@
 
 #include "EffectInfo.h"
 #include "Effects.h"
+#include "effects/Sharpen.h"
 
 using namespace openshot;
 
@@ -64,6 +65,9 @@ EffectBase* EffectInfo::CreateEffect(std::string effect_type) {
 	else if (effect_type == "Saturation")
 		return new Saturation();
 
+	else if (effect_type == "Sharpen")
+		return new Sharpen();
+
 	else if (effect_type == "Shift")
 		return new Shift();
 
@@ -134,6 +138,7 @@ Json::Value EffectInfo::JsonValue() {
 	root.append(Negate().JsonInfo());
 	root.append(Pixelate().JsonInfo());
 	root.append(Saturation().JsonInfo());
+	root.append(Sharpen().JsonInfo());
 	root.append(Shift().JsonInfo());
 	root.append(Wave().JsonInfo());
 	/* Audio */

src/effects/Sharpen.cpp

@@ -0,0 +1,353 @@
+/**
+ * Sharpen.cpp
+ * Unsharp-Mask / High-Pass effect for libopenshot
+ */
+
+#include "Sharpen.h"
+#include "Exceptions.h"
+#include <algorithm>
+#include <cmath>
+#include <vector>
+#include <omp.h>
+
+using namespace openshot;
+
+// Constructor with default keyframes
+Sharpen::Sharpen()
+  : amount(10.0)
+  , radius(3.0)
+  , threshold(0.0)
+  , mode(0)
+  , channel(0)
+{
+  init_effect_details();
+}
+
+// Constructor from keyframes
+Sharpen::Sharpen(Keyframe a, Keyframe r, Keyframe t)
+  : amount(a)
+  , radius(r)
+  , threshold(t)
+  , mode(0)
+  , channel(0)
+{
+  init_effect_details();
+}
+
+// Initialize effect metadata
+void Sharpen::init_effect_details()
+{
+  InitEffectInfo();
+  info.class_name = "Sharpen";
+  info.name        = "Sharpen";
+  info.description = "Edge-enhancing sharpen filter";
+  info.has_audio   = false;
+  info.has_video   = true;
+}
+
+// Compute three box sizes to approximate a Gaussian of sigma
+static void boxes_for_gauss(double sigma, int b[3])
+{
+  const int n = 3;
+  double wi = std::sqrt((12.0 * sigma * sigma / n) + 1.0);
+  int wl = int(std::floor(wi));
+  if (!(wl & 1)) --wl;
+  int wu = wl + 2;
+  double mi = (12.0 * sigma * sigma - n*wl*wl - 4.0*n*wl - 3.0*n)
+              / (-4.0*wl - 4.0);
+  int m = int(std::round(mi));
+  for (int i = 0; i < n; ++i)
+    b[i] = i < m ? wl : wu;
+}
+
+// Blur one axis with an edge-replicate sliding window
+static void blur_axis(const QImage& src, QImage& dst, int r, bool vertical)
+{
+  if (r <= 0) {
+    dst = src.copy();
+    return;
+  }
+
+  int W   = src.width();
+  int H   = src.height();
+  int bpl = src.bytesPerLine();
+  const uchar* in  = src.bits();
+  uchar*       out = dst.bits();
+  int window = 2*r + 1;
+
+  if (!vertical) {
+    #pragma omp parallel for
+    for (int y = 0; y < H; ++y) {
+      const uchar* rowIn  = in  + y*bpl;
+      uchar*       rowOut = out + y*bpl;
+      double sumB = rowIn[0]*(r+1), sumG = rowIn[1]*(r+1),
+             sumR = rowIn[2]*(r+1), sumA = rowIn[3]*(r+1);
+      for (int x = 1; x <= r; ++x) {
+        const uchar* p = rowIn + std::min(x, W-1)*4;
+        sumB += p[0]; sumG += p[1]; sumR += p[2]; sumA += p[3];
+      }
+      for (int x = 0; x < W; ++x) {
+        uchar* o = rowOut + x*4;
+        o[0] = uchar(sumB / window + 0.5);
+        o[1] = uchar(sumG / window + 0.5);
+        o[2] = uchar(sumR / window + 0.5);
+        o[3] = uchar(sumA / window + 0.5);
+
+        const uchar* addP = rowIn + std::min(x+r+1, W-1)*4;
+        const uchar* subP = rowIn + std::max(x-r,     0)*4;
+        sumB += addP[0] - subP[0];
+        sumG += addP[1] - subP[1];
+        sumR += addP[2] - subP[2];
+        sumA += addP[3] - subP[3];
+      }
+    }
+  }
+  else {
+    #pragma omp parallel for
+    for (int x = 0; x < W; ++x) {
+      double sumB = 0, sumG = 0, sumR = 0, sumA = 0;
+      const uchar* p0 = in + x*4;
+      sumB = p0[0]*(r+1); sumG = p0[1]*(r+1);
+      sumR = p0[2]*(r+1); sumA = p0[3]*(r+1);
+      for (int y = 1; y <= r; ++y) {
+        const uchar* p = in + std::min(y, H-1)*bpl + x*4;
+        sumB += p[0]; sumG += p[1]; sumR += p[2]; sumA += p[3];
+      }
+      for (int y = 0; y < H; ++y) {
+        uchar* o = out + y*bpl + x*4;
+        o[0] = uchar(sumB / window + 0.5);
+        o[1] = uchar(sumG / window + 0.5);
+        o[2] = uchar(sumR / window + 0.5);
+        o[3] = uchar(sumA / window + 0.5);
+
+        const uchar* addP = in + std::min(y+r+1, H-1)*bpl + x*4;
+        const uchar* subP = in + std::max(y-r,     0)*bpl + x*4;
+        sumB += addP[0] - subP[0];
+        sumG += addP[1] - subP[1];
+        sumR += addP[2] - subP[2];
+        sumA += addP[3] - subP[3];
+      }
+    }
+  }
+}
+
+// Wrapper to handle fractional radius by blending two integer passes
+static void box_blur(const QImage& src, QImage& dst, double rf, bool vertical)
+{
+  int r0 = int(std::floor(rf));
+  int r1 = r0 + 1;
+  double f = rf - r0;
+  if (f < 1e-4) {
+    blur_axis(src, dst, r0, vertical);
+  }
+  else {
+    QImage a(src.size(), QImage::Format_ARGB32);
+    QImage b(src.size(), QImage::Format_ARGB32);
+    blur_axis(src, a, r0, vertical);
+    blur_axis(src, b, r1, vertical);
+
+    int pixels = src.width() * src.height();
+    const uchar* pa = a.bits();
+    const uchar* pb = b.bits();
+    uchar*       pd = dst.bits();
+    #pragma omp parallel for
+    for (int i = 0; i < pixels; ++i) {
+      for (int c = 0; c < 4; ++c) {
+        pd[i*4+c] = uchar((1.0 - f) * pa[i*4+c]
+                        + f         * pb[i*4+c]
+                        + 0.5);
+      }
+    }
+  }
+}
+
+// Apply three sequential box blurs to approximate Gaussian
+static void gauss_blur(const QImage& src, QImage& dst, double sigma)
+{
+  int b[3];
+  boxes_for_gauss(sigma, b);
+  QImage t1(src.size(), QImage::Format_ARGB32);
+  QImage t2(src.size(), QImage::Format_ARGB32);
+
+  double r = 0.5 * (b[0] - 1);
+  box_blur(src , t1, r, false);
+  box_blur(t1, t2, r, true);
+
+  r = 0.5 * (b[1] - 1);
+  box_blur(t2, t1, r, false);
+  box_blur(t1, t2, r, true);
+
+  r = 0.5 * (b[2] - 1);
+  box_blur(t2, t1, r, false);
+  box_blur(t1, dst, r, true);
+}
+
+// Main frame processing
+std::shared_ptr<Frame> Sharpen::GetFrame(
+  std::shared_ptr<Frame> frame, int64_t frame_number)
+{
+  auto img = frame->GetImage();
+  if (!img || img->isNull())
+    return frame;
+  if (img->format() != QImage::Format_ARGB32)
+    *img = img->convertToFormat(QImage::Format_ARGB32);
+
+  int W = img->width();
+  int H = img->height();
+  if (W <= 0 || H <= 0)
+    return frame;
+
+  // Retrieve keyframe values
+  double amt   = amount.GetValue(frame_number);    // 0–40
+  double rpx   = radius.GetValue(frame_number);    // px
+  double thrUI = threshold.GetValue(frame_number); // 0–1
+
+  // Sigma scaled against 720p reference
+  double sigma = std::max(0.1, rpx * H / 720.0);
+
+  // Generate blurred image
+  QImage blur(W, H, QImage::Format_ARGB32);
+  gauss_blur(*img, blur, sigma);
+
+  int bplS = img->bytesPerLine();
+  int bplB = blur.bytesPerLine();
+  uchar* sBits = img->bits();
+  uchar* bBits = blur.bits();
+
+  #pragma omp parallel for
+  for (int y = 0; y < H; ++y) {
+    uchar* sRow = sBits + y * bplS;
+    uchar* bRow = bBits + y * bplB;
+    for (int x = 0; x < W; ++x) {
+      uchar* sp = sRow + x*4;
+      uchar* bp = bRow + x*4;
+
+      // Compute detail
+      double dB  = double(sp[0]) - double(bp[0]);
+      double dG  = double(sp[1]) - double(bp[1]);
+      double dR  = double(sp[2]) - double(bp[2]);
+      double dY  = 0.114*dB + 0.587*dG + 0.299*dR;
+      double dYn = std::abs(dY) / 255.0;
+
+      // Skip below threshold
+      if (dYn < thrUI)
+        continue;
+
+      // Halo limiter for contrast
+      auto halo = [](double d){ return (255.0 - std::abs(d)) / 255.0; };
+
+      double outC[3];
+
+      if (mode == 1) {
+        // High-Pass Blend: base = blurred + amt * detail
+        if (channel == 1) {
+          // Luma only
+          double inc = amt * dY * halo(dY);
+          for (int c = 0; c < 3; ++c)
+            outC[c] = bp[c] + inc;
+        }
+        else if (channel == 2) {
+          // Chroma only
+          double chroma[3] = { dB - dY, dG - dY, dR - dY };
+          for (int c = 0; c < 3; ++c)
+            outC[c] = bp[c] + amt * chroma[c] * halo(chroma[c]);
+        }
+        else {
+          // All channels
+          double diff[3] = { dB, dG, dR };
+          for (int c = 0; c < 3; ++c)
+            outC[c] = bp[c] + amt * diff[c] * halo(diff[c]);
+        }
+      }
+      else {
+        // Unsharp-Mask: base = original + amt * detail
+        if (channel == 1) {
+          // Luma only
+          double inc = amt * dY * halo(dY);
+          for (int c = 0; c < 3; ++c)
+            outC[c] = sp[c] + inc;
+        }
+        else if (channel == 2) {
+          // Chroma only
+          double chroma[3] = { dB - dY, dG - dY, dR - dY };
+          for (int c = 0; c < 3; ++c)
+            outC[c] = sp[c] + amt * chroma[c] * halo(chroma[c]);
+        }
+        else {
+          // All channels
+          double diff[3] = { dB, dG, dR };
+          for (int c = 0; c < 3; ++c)
+            outC[c] = sp[c] + amt * diff[c] * halo(diff[c]);
+        }
+      }
+
+      // Write back clamped
+      for (int c = 0; c < 3; ++c)
+        sp[c] = uchar(std::clamp(outC[c], 0.0, 255.0) + 0.5);
+    }
+  }
+
+  return frame;
+}
+
+// JSON serialization
+std::string Sharpen::Json() const
+{
+  return JsonValue().toStyledString();
+}
+
+Json::Value Sharpen::JsonValue() const
+{
+  Json::Value root = EffectBase::JsonValue();
+  root["type"]      = info.class_name;
+  root["amount"]    = amount.JsonValue();
+  root["radius"]    = radius.JsonValue();
+  root["threshold"] = threshold.JsonValue();
+  root["mode"]      = mode;
+  root["channel"]   = channel;
+  return root;
+}
+
+// JSON deserialization
+void Sharpen::SetJson(std::string value)
+{
+  auto root = openshot::stringToJson(value);
+  SetJsonValue(root);
+}
+
+void Sharpen::SetJsonValue(Json::Value root)
+{
+  EffectBase::SetJsonValue(root);
+  if (!root["amount"].isNull())
+    amount.SetJsonValue(root["amount"]);
+  if (!root["radius"].isNull())
+    radius.SetJsonValue(root["radius"]);
+  if (!root["threshold"].isNull())
+    threshold.SetJsonValue(root["threshold"]);
+  if (!root["mode"].isNull())
+    mode = root["mode"].asInt();
+  if (!root["channel"].isNull())
+    channel = root["channel"].asInt();
+}
+
+// Properties for UI sliders
+std::string Sharpen::PropertiesJSON(int64_t t) const
+{
+  Json::Value root = BasePropertiesJSON(t);
+  root["amount"] = add_property_json(
+    "Amount", amount.GetValue(t), "float", "", &amount, 0, 40, false, t);
+  root["radius"] = add_property_json(
+    "Radius", radius.GetValue(t), "float", "pixels", &radius, 0, 10, false, t);
+  root["threshold"] = add_property_json(
+    "Threshold", threshold.GetValue(t), "float", "ratio", &threshold, 0, 1, false, t);
+  root["mode"] = add_property_json(
+    "Mode", mode, "int", "", nullptr, 0, 1, false, t);
+  root["mode"]["choices"].append(add_property_choice_json("UnsharpMask",   0, mode));
+  root["mode"]["choices"].append(add_property_choice_json("HighPassBlend", 1, mode));
+  root["channel"] = add_property_json(
+    "Channel", channel, "int", "", nullptr, 0, 2, false, t);
+  root["channel"]["choices"].append(add_property_choice_json("All",    0, channel));
+  root["channel"]["choices"].append(add_property_choice_json("Luma",   1, channel));
+  root["channel"]["choices"].append(add_property_choice_json("Chroma", 2, channel));
+  return root.toStyledString();
+}

src/effects/Sharpen.h

@@ -0,0 +1,80 @@
+// Sharpen.h
+/**
+ * @file
+ * @brief Header file for Sharpen effect class
+ * @author Jonathan Thomas <jonathan@openshot.org>
+ *
+ * @ref License
+ */
+
+#ifndef OPENSHOT_SHARPEN_EFFECT_H
+#define OPENSHOT_SHARPEN_EFFECT_H
+
+#include "EffectBase.h"
+#include "KeyFrame.h"
+#include "Json.h"
+
+#include <string>
+
+namespace openshot {
+
+/**
+ * @brief This class provides a sharpen effect for video frames.
+ *
+ * The sharpen effect enhances the edges and details in a video frame, making it appear sharper.
+ * It uses an unsharp mask or high-pass blend technique with adjustable parameters.
+ */
+class Sharpen : public EffectBase {
+private:
+    /// Initialize the effect details
+    void init_effect_details();
+
+public:
+    /// Amount of sharpening to apply (0 to 2)
+    Keyframe amount;
+
+    /// Radius of the blur used in sharpening (0 to 10 pixels for 1080p)
+    Keyframe radius;
+
+    /// Threshold for applying sharpening (0 to 1)
+    Keyframe threshold;
+
+    /// Sharpening mode (0 = UnsharpMask, 1 = HighPassBlend)
+    int mode;
+
+    /// Channel to apply sharpening to (0 = All, 1 = Luma, 2 = Chroma)
+    int channel;
+
+    /// Default constructor
+    Sharpen();
+
+    /// Constructor with initial values
+    Sharpen(Keyframe new_amount, Keyframe new_radius, Keyframe new_threshold);
+
+    /// @brief This method is required for all derived classes of EffectBase, and returns a
+    /// modified openshot::Frame object
+    ///
+    /// The frame object is passed into this method, and a frame_number is passed in which
+    /// tells the effect which settings to use from its keyframes (starting at 1).
+    ///
+    /// @returns The modified openshot::Frame object
+    /// @param frame The frame object that needs the effect applied to it
+    /// @param frame_number The frame number (starting at 1) of the effect on the timeline.
+    std::shared_ptr<Frame> GetFrame(std::shared_ptr<Frame> frame, int64_t frame_number) override;
+    std::shared_ptr<Frame> GetFrame(int64_t n) override
+    { return GetFrame(std::make_shared<Frame>(), n); }
+
+    /// Get and Set JSON methods
+    std::string Json() const override; ///< Generate JSON string of this object
+    Json::Value JsonValue() const override; ///< Generate Json::Value for this object
+    void SetJson(const std::string value) override; ///< Load JSON string into this object
+    void SetJsonValue(const Json::Value root) override; ///< Load Json::Value into this object
+
+    /// Get all properties for a specific frame (perfect for a UI to display the current state
+    /// of all properties at any time)
+    std::string PropertiesJSON(int64_t requested_frame) const override;
+};
+
+}  // namespace openshot
+
+#endif  // OPENSHOT_SHARPEN_EFFECT_H