Reco areas

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What is it?

Reco Areas are areas that user can create and modify. They consist in areas in the marker that will be used by BIRS ( Bear Image Recognition System). If a marker has reco areas, they will be the only source used to identify and track the marker. This eases a lot the production process of augmentation of complex markers (newspaperノ), where multiple markers often have identical headers, footers, blocksノ These elements can be considered as duplicates and can cause unexpected behavior.

Reco Areas will "crop" the area used by BIRS, allowing to discard unwanted parts of the markers. This will speed up - a lot - the process of doing image manipulation with photoshop-gimpノ to remove problematic parts of the marker.

 

How does it work?

First of all, you need a marker and its page_id. To compute area coordinates, usage of scale conversion formula is needed. You need: reco area x, y, width and height relative to marker size. Pseudocode :

maxSide = max(markerWidth, markerHeight);
rx = (x + max(0,markerHeight - markerWidth)/2) / maxSide - 0.5;
ry = (y + max(0,markerWidth - markerHeight)/2) / maxSide - 0.5;
rwidth = width / maxSide;
rheight = height / maxSide;
rx += (rwidth / 2);
ry += (rheight / 2) ;

 

Reco areas coordinate system

All the coordinates are relative to the markers biggest side.

Reco areas coordinates

API calls:

Create reco area: POST api.bear2b.com/reco_areas Parameters:

name description
page_id Marker ID
cx Reco areaユs center point X coordinate
cy Reco areaユs center point Y coordinate
width Reco areaユs width
height Reco areaユs height

In case of success new reco area created and attached to original marker. Response:

id Reco areaユs ID
page_id Marker ID
area_target_id Reco area unique ID used in recognition
cx Reco areaユs center point X coordinate
cy Reco areaユs center point Y coordinate
width Reco areaユs width
height Reco areaユs height
image Path to the reco area image

Update reco area: PUT api.bear2b.com/reco_areas

Parameters:

name description
id Reco areaユs ID
cx Reco areaユs center point X coordinate
cy Reco areaユs center point Y coordinate
width Reco areaユs width
height Reco areaユs height

Response:

name description
id Reco areaユs ID
page_id Marker ID
area_target_id Reco area unique ID used in recognition
cx Reco areaユs center point X coordinate
cy Reco areaユs center point Y coordinate
width Reco areaユs width
height Reco areaユs height
image Path to the reco area image

Delete reco area: PUT api.bear2b.com/reco_areas

Parameters:

name description
id Reco areaユs ID

Get all reco areas for the specified marker: GET api.bear2b.com/reco_areas

Parameters:

name description
page_id Marker ID

Response: Array of objects:

name description
id Reco areaユs ID
page_id Marker ID
area_target_id Reco area unique ID used in recognition
cx Reco areaユs center point X coordinate
cy Reco areaユs center point Y coordinate
width Reco areaユs width
height Reco areaユs height
image Path to the reco area image

 

Example

reco example

For these markers we can observe that there are "duplicate warning" displayed by BIRS. To avoid them we'll create two reco areas per marker.

reco example areas

Our marker having dimensions of 529x699px, for the top reco area, our first reco area top left corner needs to be at x = 0, y = 0, having a width of 529 and height of ‾135. We apply the pseudocode:

maxSide = max(529, 699); // = 699 
rx = (0 + max(0,699 - 529)/2) / 699 - 0.5; // = ‾ -0,378397711
ry = (0 + max(0,529 - 699)/2) / 699 - 0.5; // = -0,5
rwidth = 529 / 699; // = 0,756795422
rheight = 135 / 699; // = 0,1931330472
rx += (rwidth / 2); // = 0
ry += (rheight / 2) ; // = -0,4034334764

Then we can do the API call with our new data, supposing that page_id is 42 api.bear2b.com/reco_areas-post.php?page_id=42&cx=0&cy=-0.4034334764&width=0.756795422&height=0.1931330472

We repeat same operation for the bottom reco area.

 

ARGO Platform

The ability to create a single reco area will be available soon in our platform. It allows to create reco areas easily. Once a marker has been created, you can open the edit recognition parameters modal.

reco example

Then you can click the "crop" button.

reco example

Then, a resizable box appears, that represents the reco area. Here we just use the header title, and not the logo "20 minutes" of the newspaper. We hit Save, and the call generated is : api.bear2b.com/reco_areas-post.php?page_id=42&cx=0.09514&cy=-0.40486&width=0.552217&height=0.178827

GO will allow modification of one single reco area. Support for multiple reco areas will be available soon.

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