Add tensor for Ultra-Light-Fast-Generic-Face-Detector without post processing

Ref: https://github.com/Linzaer/Ultra-Light-Fast-Generic-Face-Detector-1MB/

Author: ocrete

tensor-id-register.md

@@ -9,6 +9,7 @@
 |classification-generic-out | [details](/tensors/classification-generic-out.md) |
 |classification-generic-softmaxed-out | [details](/tensors/classification-generic-softmaxed-out.md) |
 |ultra-lightweight-face-detection-rfb-320-v1-variant-1-out-scores | [details](/tensors/ultra-lightweight-face-detection-rfb-320-v1-variant-1-out-scores.md) |
+|ultra-lightweight-face-detection-rfb-320-v1-variant-1-out-boxes-without-postproc | [details](/tensors/ultra-lightweight-face-detection-rfb-320-v1-variant-1-out-boxes-without-postproc.md) |
 |yolo-v8-pose-out | [details](/tensors/yolo-v8-pose-out.md) |
 |yolo-v8-segmentation-out-detections | [details](/tensors/yolo-v8-segmentation-out-detections.md) |
 |yolo-v8-segmentation-out-protos | [details](/tensors/yolo-v8-segmentation-out-protos.md) |

tensors/ultra-lightweight-face-detection-rfb-320-v1-variant-1-out-boxes-without-postproc.md

@@ -0,0 +1,78 @@
+# Classification
+
+- tensor-group: no
+- layer-type: output
+- use-case: face-detection
+
+# Description
+Location of faces detected
+
+## Boxes Tensor
+
+- tensor-shape: 1 x COUNT x 4
+- tensor-datatype: float32
+- tensor-id: ultra-lightweight-face-detection-rfb-320-v1-variant-1-out-boxes-without-postproc
+
+### Encoding
+
+Scheme: (top left X, top left Y, width, height)
+
+The COUNT is variable and depends on the model training.
+
+Other constants are extracted from the training process:
+- CENTER_VARIANCE = 0.1
+- SIZE_VARIANCE = 0.2
+- COUNT
+
+The COUNT can be retrieved from the tensor dimensions.
+
+Each entry in the table is the variance on the matching anchor which
+is also defined at training time. Each anchor is defined as the
+following tuple:
+`(anchor-center-x, anchor-center-y, anchor-width anchor-height)`
+
+Once the following formulas have been applied, the bounding boxes
+center is calculated along with its size.
+
+```
+bounding-box-center-x = top-left-x * CENTER_VARIANCE * anchor-width + anchor-center-x
+bounding-box-center-y = top-left-y * CENTER_VARIANCE * anchor-height + anchor-center-y
+bounding-box-width = expf (width * SIZE_VARIANCE) * anchor-width
+bounding-box-height = expf (height * SIZE_VARIANCE) * anchor-height
+```
+
+|box-1 | box-1 | box-1 | box-1 | box-2 | box-2 | box-2 | box-2 | ... | COUNT|COUNT|COUNT|COUNT|
+|---   |---    |---    |---    |---    |---    |---    |---    |---  |---                |---                |---                |---                |
+| top-left-X | top-left-Y | width | height | top-left-X | top-left-Y | width | height | ...  top-left-X | top-left-Y | width | height |
+
+Memory layout of tensor data:
+
+|Index                |Value              |
+|---                  |---                |
+| -                   | -                 |
+|0                    |top-left-x         |
+|1                    |top-left-y         |
+|2                    |width              |
+|3                    |height             |
+|4                    |top-left-x         |
+|5                    |top-left-y         |
+|6                    |width              |
+|7                    |height             |
+|...                  | ...               |
+|(COUNT - 1) x 4      |top-left-x         |
+|(COUNT - 1) x 4 + 1  |top-left-y         |
+|(COUNT - 1) x 4 + 2  |width              |
+|(COUNT - 1) x 4 + 3  |height             |
+
+
+
+# Models
+
+* [Model source](https://github.com/Linzaer/Ultra-Light-Fast-Generic-Face-Detector-1MB/tree/master)
+* [ONNX pre-trained model](https://github.com/Linzaer/Ultra-Light-Fast-Generic-Face-Detector-1MB/tree/master/models/)
+
+# Tensor Decoders
+|Framework | Links |
+|---       |---    |
+|GStreamer | [perm](https://gitlab.freedesktop.org/gstreamer/gstreamer/-/blob/main/subprojects/gst-plugins-bad/gst/tensordecoders/gstfacedetectortensordecoder.c) |
+