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rakesh kumar
rakesh kumar

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How to calculate bounding box using anchor in faster rcnn for object detection in deep learning

In Faster R-CNN, the bounding box predictions are generated by the Region Proposal Network (RPN) based on the anchors. The RPN predicts adjustments to the anchor boxes to obtain more accurate bounding box coordinates. The formulas for calculating the bounding box coordinates using anchors are as follows:

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def calculate_final_bbox(anchor, rpn_predictions):
    x_anchor, y_anchor, w_anchor, h_anchor = anchor
    delta_x, delta_y, delta_w, delta_h = rpn_predictions

    x_adjusted = x_anchor + delta_x * w_anchor
    y_adjusted = y_anchor + delta_y * h_anchor

    w_adjusted = w_anchor * np.exp(delta_w)
    h_adjusted = h_anchor * np.exp(delta_h)

    x_final = x_adjusted - w_adjusted / 2
    y_final = y_adjusted - h_adjusted / 2

    return x_final, y_final, w_adjusted, h_adjusted

# Example usage:
anchor_box = (10, 20, 30, 40)
rpn_predictions = (0.1, -0.2, 0.3, -0.1)

final_bbox = calculate_final_bbox(anchor_box, rpn_predictions)
print("Final Bounding Box:", final_bbox)
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Make sure to replace the anchor_box and rpn_predictions variables with the actual values from your model's output. The final_bbox variable will contain the calculated bounding box coordinates.

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