ChromaKey.cpp
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/**
* @file
* @brief Source file for ChromaKey class
* @author Jonathan Thomas <jonathan@openshot.org>
*
* @section LICENSE
*
* Copyright (c) 2008-2014 OpenShot Studios, LLC
* <http://www.openshotstudios.com/>. This file is part of
* OpenShot Library (libopenshot), an open-source project dedicated to
* delivering high quality video editing and animation solutions to the
* world. For more information visit <http://www.openshot.org/>.
*
* OpenShot Library (libopenshot) is free software: you can redistribute it
* and/or modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* OpenShot Library (libopenshot) is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "../../include/effects/ChromaKey.h"
using namespace openshot;
/// Blank constructor, useful when using Json to load the effect properties
ChromaKey::ChromaKey() : fuzz(5.0) {
// Init default color
color = Color();
// Init effect properties
init_effect_details();
}
// Default constructor, which takes an openshot::Color object and a 'fuzz' factor, which
// is used to determine how similar colored pixels are matched. The higher the fuzz, the
// more colors are matched.
ChromaKey::ChromaKey(Color color, Keyframe fuzz) : color(color), fuzz(fuzz)
{
// Init effect properties
init_effect_details();
}
// Init effect settings
void ChromaKey::init_effect_details()
{
/// Initialize the values of the EffectInfo struct.
InitEffectInfo();
/// Set the effect info
info.class_name = "ChromaKey";
info.name = "Chroma Key (Greenscreen)";
info.description = "Replaces the color (or chroma) of the frame with transparency (i.e. keys out the color).";
info.has_audio = false;
info.has_video = true;
}
// This method is required for all derived classes of EffectBase, and returns a
// modified openshot::Frame object
std::shared_ptr<Frame> ChromaKey::GetFrame(std::shared_ptr<Frame> frame, int64_t frame_number)
{
// Determine the current HSL (Hue, Saturation, Lightness) for the Chrome
int threshold = fuzz.GetInt(frame_number);
long mask_R = color.red.GetInt(frame_number);
long mask_G = color.green.GetInt(frame_number);
long mask_B = color.blue.GetInt(frame_number);
// Get source image's pixels
std::shared_ptr<QImage> image = frame->GetImage();
unsigned char *pixels = (unsigned char *) image->bits();
// Loop through pixels
for (int pixel = 0, byte_index=0; pixel < image->width() * image->height(); pixel++, byte_index+=4)
{
// Get the RGB values from the pixel
unsigned char R = pixels[byte_index];
unsigned char G = pixels[byte_index + 1];
unsigned char B = pixels[byte_index + 2];
unsigned char A = pixels[byte_index + 3];
// Get distance between mask color and pixel color
long distance = Color::GetDistance((long)R, (long)G, (long)B, mask_R, mask_G, mask_B);
// Alpha out the pixel (if color similar)
if (distance <= threshold)
// MATCHED - Make pixel transparent
pixels[byte_index + 3] = 0;
}
// return the modified frame
return frame;
}
// Generate JSON string of this object
string ChromaKey::Json() {
// Return formatted string
return JsonValue().toStyledString();
}
// Generate Json::JsonValue for this object
Json::Value ChromaKey::JsonValue() {
// Create root json object
Json::Value root = EffectBase::JsonValue(); // get parent properties
root["type"] = info.class_name;
root["color"] = color.JsonValue();
root["fuzz"] = fuzz.JsonValue();
// return JsonValue
return root;
}
// Load JSON string into this object
void ChromaKey::SetJson(string value) {
// Parse JSON string into JSON objects
Json::Value root;
Json::Reader reader;
bool success = reader.parse( value, root );
if (!success)
// Raise exception
throw InvalidJSON("JSON could not be parsed (or is invalid)", "");
try
{
// Set all values that match
SetJsonValue(root);
}
catch (exception e)
{
// Error parsing JSON (or missing keys)
throw InvalidJSON("JSON is invalid (missing keys or invalid data types)", "");
}
}
// Load Json::JsonValue into this object
void ChromaKey::SetJsonValue(Json::Value root) {
// Set parent data
EffectBase::SetJsonValue(root);
// Set data from Json (if key is found)
if (!root["color"].isNull())
color.SetJsonValue(root["color"]);
if (!root["fuzz"].isNull())
fuzz.SetJsonValue(root["fuzz"]);
}
// Get all properties for a specific frame
string ChromaKey::PropertiesJSON(int64_t requested_frame) {
// Generate JSON properties list
Json::Value root;
root["id"] = add_property_json("ID", 0.0, "string", Id(), NULL, -1, -1, true, requested_frame);
root["position"] = add_property_json("Position", Position(), "float", "", NULL, 0, 30 * 60 * 60 * 48, false, requested_frame);
root["layer"] = add_property_json("Track", Layer(), "int", "", NULL, 0, 20, false, requested_frame);
root["start"] = add_property_json("Start", Start(), "float", "", NULL, 0, 30 * 60 * 60 * 48, false, requested_frame);
root["end"] = add_property_json("End", End(), "float", "", NULL, 0, 30 * 60 * 60 * 48, false, requested_frame);
root["duration"] = add_property_json("Duration", Duration(), "float", "", NULL, 0, 30 * 60 * 60 * 48, true, requested_frame);
// Keyframes
root["color"] = add_property_json("Key Color", 0.0, "color", "", NULL, 0, 255, false, requested_frame);
root["color"]["red"] = add_property_json("Red", color.red.GetValue(requested_frame), "float", "", &color.red, 0, 255, false, requested_frame);
root["color"]["blue"] = add_property_json("Blue", color.blue.GetValue(requested_frame), "float", "", &color.blue, 0, 255, false, requested_frame);
root["color"]["green"] = add_property_json("Green", color.green.GetValue(requested_frame), "float", "", &color.green, 0, 255, false, requested_frame);
root["fuzz"] = add_property_json("Fuzz", fuzz.GetValue(requested_frame), "float", "", &fuzz, 0, 25, false, requested_frame);
// Return formatted string
return root.toStyledString();
}
openshot::Color::JsonValue
Json::Value JsonValue()
Generate Json::JsonValue for this object.
Definition: Color.cpp:92
openshot::EffectBase::info
EffectInfoStruct info
Information about the current effect.
Definition: EffectBase.h:73
openshot::ChromaKey::SetJson
void SetJson(string value)
Load JSON string into this object.
Definition: ChromaKey.cpp:121
openshot::ChromaKey::Json
string Json()
Get and Set JSON methods.
Definition: ChromaKey.cpp:101
openshot::Color::green
Keyframe green
Curve representing the green value (0 - 255)
Definition: Color.h:46
openshot::ClipBase::Id
void Id(string value)
Set basic properties.
Definition: ClipBase.h:90
openshot
This namespace is the default namespace for all code in the openshot library.
Definition: AudioBufferSource.h:45
openshot::EffectInfoStruct::class_name
string class_name
The class name of the effect.
Definition: EffectBase.h:51
openshot::Color::SetJsonValue
void SetJsonValue(Json::Value root)
Load Json::JsonValue into this object.
Definition: Color.cpp:129
openshot::Keyframe::GetInt
int GetInt(int64_t index)
Get the rounded INT value at a specific index.
Definition: KeyFrame.cpp:248
openshot::ChromaKey::JsonValue
Json::Value JsonValue()
Generate Json::JsonValue for this object.
Definition: ChromaKey.cpp:108
openshot::Color::GetDistance
static long GetDistance(long R1, long G1, long B1, long R2, long G2, long B2)
Get the distance between 2 RGB pairs. (0=identical colors, 10=very close colors, 760=very different c...
Definition: Color.cpp:75
openshot::EffectBase::JsonValue
virtual Json::Value JsonValue()=0
Generate Json::JsonValue for this object.
Definition: EffectBase.cpp:81
openshot::ClipBase::add_property_json
Json::Value add_property_json(string name, float value, string type, string memo, Keyframe *keyframe, float min_value, float max_value, bool readonly, int64_t requested_frame)
Generate JSON for a property.
Definition: ClipBase.cpp:65
openshot::Color
This class represents a color (used on the timeline and clips)
Definition: Color.h:42
openshot::Keyframe::GetValue
double GetValue(int64_t index)
Get the value at a specific index.
Definition: KeyFrame.cpp:226
openshot::Keyframe
A Keyframe is a collection of Point instances, which is used to vary a number or property over time.
Definition: KeyFrame.h:64
openshot::InvalidJSON
Exception for invalid JSON.
Definition: Exceptions.h:152
openshot::ChromaKey::SetJsonValue
void SetJsonValue(Json::Value root)
Load Json::JsonValue into this object.
Definition: ChromaKey.cpp:144
openshot::EffectBase::InitEffectInfo
void InitEffectInfo()
Definition: EffectBase.cpp:33
openshot::EffectInfoStruct::has_audio
bool has_audio
Determines if this effect manipulates the audio of a frame.
Definition: EffectBase.h:56
openshot::Color::blue
Keyframe blue
Curve representing the red value (0 - 255)
Definition: Color.h:47
openshot::EffectInfoStruct::description
string description
The description of this effect and what it does.
Definition: EffectBase.h:54
openshot::Keyframe::JsonValue
Json::Value JsonValue()
Generate Json::JsonValue for this object.
Definition: KeyFrame.cpp:321
openshot::EffectInfoStruct::name
string name
The name of the effect.
Definition: EffectBase.h:53
openshot::ChromaKey::PropertiesJSON
string PropertiesJSON(int64_t requested_frame)
Definition: ChromaKey.cpp:157
openshot::EffectBase::SetJsonValue
virtual void SetJsonValue(Json::Value root)=0
Load Json::JsonValue into this object.
Definition: EffectBase.cpp:121
OpenShot Wipe Tests.e
e
Definition: OpenShot Wipe Tests.py:28
openshot::EffectInfoStruct::has_video
bool has_video
Determines if this effect manipulates the image of a frame.
Definition: EffectBase.h:55
openshot::Color::red
Keyframe red
Curve representing the red value (0 - 255)
Definition: Color.h:45
openshot::Keyframe::SetJsonValue
void SetJsonValue(Json::Value root)
Load Json::JsonValue into this object.
Definition: KeyFrame.cpp:362
openshot::ChromaKey::ChromaKey
ChromaKey()
Blank constructor, useful when using Json to load the effect properties.
Definition: ChromaKey.cpp:33
openshot::ChromaKey::GetFrame
std::shared_ptr< Frame > GetFrame(std::shared_ptr< Frame > frame, int64_t frame_number)
This method is required for all derived classes of EffectBase, and returns a modified openshot::Frame...
Definition: ChromaKey.cpp:66