From bbf98a017677082a436f07da47f04103b7bb0aa9 Mon Sep 17 00:00:00 2001 From: qingqing01 Date: Mon, 5 Mar 2018 13:47:53 +0800 Subject: [PATCH] Refine the doc in detection_output API. (#8689) * Refine the doc in detection_output API. * Refine the doc. --- python/paddle/fluid/layers/detection.py | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) diff --git a/python/paddle/fluid/layers/detection.py b/python/paddle/fluid/layers/detection.py index a077c0ce334..d16b4dc3a48 100644 --- a/python/paddle/fluid/layers/detection.py +++ b/python/paddle/fluid/layers/detection.py @@ -54,11 +54,17 @@ def detection_output(loc, score_threshold=0.01, nms_eta=1.0): """ - **Detection Output Layer** + **Detection Output Layer for Single Shot Multibox Detector (SSD).** - This layer applies the NMS to the output of network and computes the - predict bounding box location. The output's shape of this layer could - be zero if there is no valid bounding box. + This operation is to get the detection results by performing following + two steps: + + 1. Decode input bounding box predictions according to the prior boxes. + 2. Get the final detection results by applying multi-class non maximum + suppression (NMS). + + Please note, this operation doesn't clip the final output bounding boxes + to the image window. Args: loc(Variable): A 3-D Tensor with shape [N, M, 4] represents the @@ -91,7 +97,15 @@ def detection_output(loc, nms_eta(float): The parameter for adaptive NMS. Returns: - The detected bounding boxes which are a Tensor. + Variable: The detection outputs is a LoDTensor with shape [No, 6]. + Each row has six values: [label, confidence, xmin, ymin, xmax, ymax]. + `No` is the total number of detections in this mini-batch. For each + instance, the offsets in first dimension are called LoD, the offset + number is N + 1, N is the batch size. The i-th image has + `LoD[i + 1] - LoD[i]` detected results, if it is 0, the i-th image + has no detected results. If all images have not detected results, + all the elements in LoD are 0, and output tensor only contains one + value, which is -1. Examples: .. code-block:: python -- GitLab