Intelligent Image Scissor for COMP5421 CV Pro1

Requirement

Qt5, OpenCV3, Ubuntu

sudo apt install qt5-default libopencv3

Installation && Run gui

cd image_scissor
qmake image_scissor.pro
make -j
./image_scissor

Usage

1. Open an image: Ctrl+F

2. Set a seed: Ctrl+Space & Left Click
3. Move your mouse to edit the contour
4. Save the mask: Ctrl+Shift+S

Debug Mode

1. You can click the above menu to see the cost Pixel Node, Cost Graph, Minimum Path Tree

For example: Cost Graph

Demo Video

TODO List

1. Implement other features on GUI

• Help menu and about window
• Grids at image Viewer

2. Algorithm

• Generate Path on Minimum Path Tree

Some Bugs I made at this project

1. Usage of priority_queue in STL

• This kind of container does't provide a erase and update operation.
• The other problem is that we can only chage the state of each node in priority_queue but can not change the date value(related to priority), otherwise it will destory the order the queue(the order won't change).
• So you need to use other struction(like vector or array to record the current state of each node), and then add them into queue.
• The solution I found is like this:

• std::priority_queue<Node::Ptr, std::vector<Node::Ptr>, ValueComp> pqueue;
• std::vector<vector<Node::Ptr> > _node_graph;
• Node::Ptr p = _pqueue.top();
• if (p->_state == EXPANDEND) continue; // to discard useless node
• p->_state = EXPANDEND; // the state of all p in queue are changed, meaning that they will be discarded
• ii, jj \\ the position of extended point r
• r = _node_graph[ii][jj]
• r->_total_cost = min(r->_total_cost, p->_total_cost + c_pr); // is changed
• pqueue.push(r) // push new node

2. Usage of floodfill algorithm

• My unstanding: after setting a seed, just go around, until meet a mountain(the difference of pixel is larger than threshold)