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Update EX_SIMPLE_IMAGE_STABILIZATION.hpp
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@lauriebose
lauriebose committed Jan 17, 2025
1 parent 886f941 commit 8163bb2
Showing 1 changed file with 79 additions and 49 deletions.
128 changes: 79 additions & 49 deletions EXAMPLES/EX_SIMPLE_IMAGE_STABILIZATION.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -33,11 +33,15 @@ int main()
vs_handle display_00 = vs_gui_add_display("Stabilized Image",0,0,display_size);
vs_handle display_01 = vs_gui_add_display("Captured Image",0,display_size,display_size);

//The variables used to store how the current image should be shifted to align it with the stored key-frame
//Note this is a very simple method in that it only aligns via translation, and does not account for rotation & scaling
int alignment_x = 0; int alignment_y = 0;
int vel_x = 0; int vel_y = 0;

//Varibles used to keep track of alignment "velocity", allows more robust alignment under motion by estimating the new alignment each frame using this "velocity"
int alignment_vel_x = 0; int alignment_vel_y = 0;

int use_inertia = 1;
vs_gui_add_switch("use_inertia",1,&use_inertia);
int use_velocity = 1;
vs_gui_add_switch("use_velocity",1,&use_velocity);

bool set_anchor_image = false;
auto gui_btn_set_anchor_image = vs_gui_add_button("set_anchor_image");
Expand All @@ -49,6 +53,12 @@ int main()
int edge_threshold = 12;
vs_gui_add_slider("edge_threshold x",0,127,edge_threshold,&edge_threshold);

int alignment_strength = 0;
int minimum_alignment_strength = 2000;
vs_gui_add_slider("minimum_alignment_strength",0,4000,minimum_alignment_strength,&minimum_alignment_strength);

int show_current_edge_image = 1;
vs_gui_add_switch("show_captured_image",1,&show_current_edge_image);

// Frame Loop
while(1)
Expand All @@ -58,6 +68,13 @@ int main()
vs_disable_frame_trigger();
vs_frame_loop_control();

if(alignment_strength < minimum_alignment_strength)
{
set_anchor_image = true;
vs_post_text("insufficient edges");
}
alignment_strength = 0;

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//CAPTURE FRAME

Expand Down Expand Up @@ -120,19 +137,13 @@ int main()
OR(DREG_combined_edges,DREG_horizontal_edges);//OR WITH HORIZONTAL EDGE RESULT
scamp5_kernel_end();


int position_threshold = 48;
if(abs(alignment_x) > position_threshold || abs(alignment_y) > position_threshold)
{
set_anchor_image = true;
}
if(set_anchor_image)
{
set_anchor_image = false;
alignment_x = 0;
alignment_y = 0;
vel_x = 0;
vel_y = 0;
alignment_vel_x = 0;
alignment_vel_y = 0;

scamp5_kernel_begin();
MOV(DREG_keyframe_edges,DREG_combined_edges);
Expand All @@ -147,26 +158,26 @@ int main()
//IMAGE ALIGNMENT
//This code updates the "position" at which the captured image aligns with the stored key-frame

if(use_inertia)
if(use_velocity)
{
alignment_x += vel_x;
alignment_y += vel_y;
alignment_x += alignment_vel_x;
alignment_y += alignment_vel_y;
}

//Copy the latest edge frame and shift it to the previous position determined to align with the edge key-frame
//Copy the latest edge frame and shift it to the position determined to align with the edge key-frame
scamp5_kernel_begin();
MOV(S4,S1);
scamp5_kernel_end();
scamp5_shift(S4,alignment_x,alignment_y);

//The directions to shift and test for better alignment (i.e. noshift,left,right,down,up)
//The shifts to test and see if they improve image alignment with the keyframe
int test_shift_directions[][5] =
{
{0,0},
{1,0},
{-1, 0},
{0,1},
{0, -1},
{0,0},//no shift
{1,0},//left
{-1, 0},//right
{0,1},//down
{0, -1},//up
};

//Array to store the global summations for each tested shift
Expand All @@ -175,14 +186,14 @@ int main()
//Test each shift
for (int n = 0; n < 5; n++)
{
int x = test_shift_directions[n][0];
int y = test_shift_directions[n][1];
int shift_x = test_shift_directions[n][0];
int shift_y = test_shift_directions[n][1];

//Copy the shifted edge frame & apply the test shift to it
scamp5_kernel_begin();
MOV(S6,S4);
scamp5_kernel_end();
scamp5_shift(S6,x,y);
scamp5_shift(S6,shift_x,shift_y);

scamp5_in(F,127);
scamp5_kernel_begin();
Expand All @@ -193,38 +204,57 @@ int main()
mov(D,F);//D = 127 in PEs where the edges of
ALL();
scamp5_kernel_end();

direction_global_sums[n] = scamp5_global_sum_64(D);

//The highest value sum will have the best alignment, ie. the most overlap between the edge from the current frame and the key-frame
if(alignment_strength < direction_global_sums[n])
{
alignment_strength = direction_global_sums[n];
}
}

if(direction_global_sums[0] > direction_global_sums[1] &&
direction_global_sums[0] > direction_global_sums[2] &&
direction_global_sums[0] > direction_global_sums[3] &&
direction_global_sums[0] > direction_global_sums[4])
direction_global_sums[0] > direction_global_sums[2] &&
direction_global_sums[0] > direction_global_sums[3] &&
direction_global_sums[0] > direction_global_sums[4])
{

//The best alignment was when no shift was applied at all so nothing need be updated
}
else
{
if(direction_global_sums[1] < direction_global_sums[2])
{
alignment_x--;
vel_x--;
}
else
{
alignment_x++;
vel_x++;
}
//Determine which horizontal and vertical shift directions that improved alignment, and update the alignment & "velocity"

if(direction_global_sums[3] < direction_global_sums[4])
//Did either shifting left or right result in a better alignment than not shifting at all?
if(direction_global_sums[0] < direction_global_sums[1] || direction_global_sums[0] < direction_global_sums[2])
{
alignment_y--;
vel_y--;
//Compare the summation from shifting left and right
if(direction_global_sums[1] < direction_global_sums[2])
{
alignment_x--;
alignment_vel_x--;
}
else
{
alignment_x++;
alignment_vel_x++;
}
}
else

//Did either shifting left or right result in a better alignment than not shifting at all?
if(direction_global_sums[0] < direction_global_sums[3] || direction_global_sums[0] < direction_global_sums[4])
{
alignment_y++;
vel_y++;
//Compare the summation from shifting up and down
if(direction_global_sums[3] < direction_global_sums[4])
{
alignment_y--;
alignment_vel_y--;
}
else
{
alignment_y++;
alignment_vel_y++;
}
}
}

Expand All @@ -245,11 +275,11 @@ int main()
scamp5_kernel_end();
scamp5_output_image(S6,display_00);

scamp5_output_image(S1,display_01);



// scamp5_output_image(DREG_keyframe_edges,display_02);
if(show_current_edge_image)
{
scamp5_output_image(S1,display_01);
}
vs_post_text("alignment (%d,%d), velocity (%d,%d), strength %d \n",alignment_x,alignment_y,alignment_vel_x,alignment_vel_y,alignment_strength);
}
int image_output_time_microseconds = output_timer.get_usec();//get the time taken for image output

Expand Down

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