FastDeploy/csrc/fastdeploy/vision/visualize/swap_background.cc

// Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifdef ENABLE_VISION_VISUALIZE

#include "fastdeploy/vision/visualize/visualize.h"
#include "opencv2/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"

namespace fastdeploy {
namespace vision {

cv::Mat Visualize::SwapBackgroundMatting(const cv::Mat& im,
                                         const cv::Mat& background,
                                         const MattingResult& result,
                                         bool remove_small_connected_area) {
  // 只可视化alpha，fgr(前景)本身就是一张图 不需要可视化
  FDASSERT((!im.empty()), "Image can't be empty!");
  FDASSERT((im.channels() == 3), "Only support 3 channels image mat!");
  FDASSERT((!background.empty()), "Background image can't be empty!");
  FDASSERT((background.channels() == 3),
           "Only support 3 channels background image mat!");
  auto vis_img = im.clone();
  auto background_copy = background.clone();
  int out_h = static_cast<int>(result.shape[0]);
  int out_w = static_cast<int>(result.shape[1]);
  int height = im.rows;
  int width = im.cols;
  int bg_height = background.rows;
  int bg_width = background.cols;
  // alpha to cv::Mat && 避免resize等操作修改外部数据
  std::vector<float> alpha_copy;
  alpha_copy.assign(result.alpha.begin(), result.alpha.end());
  float* alpha_ptr = static_cast<float*>(alpha_copy.data());
  cv::Mat alpha(out_h, out_w, CV_32FC1, alpha_ptr);
  if (remove_small_connected_area) {
    alpha = Visualize::RemoveSmallConnectedArea(alpha, 0.05f);
  }
  if ((vis_img).type() != CV_8UC3) {
    (vis_img).convertTo((vis_img), CV_8UC3);
  }
  if ((background_copy).type() != CV_8UC3) {
    (background_copy).convertTo((background_copy), CV_8UC3);
  }
  if ((bg_height != height) || (bg_width != width)) {
    cv::resize(background, background_copy, cv::Size(width, height));
  }
  if ((out_h != height) || (out_w != width)) {
    cv::resize(alpha, alpha, cv::Size(width, height));
  }
  uchar* vis_data = static_cast<uchar*>(vis_img.data);
  uchar* background_data = static_cast<uchar*>(background_copy.data);
  uchar* im_data = static_cast<uchar*>(im.data);
  float* alpha_data = reinterpret_cast<float*>(alpha.data);
  for (size_t i = 0; i < height; ++i) {
    for (size_t j = 0; j < width; ++j) {
      float alpha_val = alpha_data[i * width + j];
      for (size_t c = 0; c < 3; ++c) {
        vis_data[i * width * 3 + j * 3 + c] = cv::saturate_cast<uchar>(
            static_cast<float>(im_data[i * width * 3 + j * 3 + c]) * alpha_val +
            (1.f - alpha_val) * background_data[i * width * 3 + j * 3 + c]);
      }
    }
  }

  return vis_img;
}
// 对SegmentationResult做背景替换，由于分割模型可以预测多个类别，其中
// background_label 表示预测为背景类的标签
// 由于不同模型和数据集训练的背景类别标签可能不同，用户可以自己输入背景类对应的标签。
cv::Mat Visualize::SwapBackgroundSegmentation(
    const cv::Mat& im, const cv::Mat& background, int background_label,
    const SegmentationResult& result) {
  FDASSERT((!im.empty()), "Image can't be empty!");
  FDASSERT((im.channels() == 3), "Only support 3 channels image mat!");
  FDASSERT((!background.empty()), "Background image can't be empty!");
  FDASSERT((background.channels() == 3),
           "Only support 3 channels background image mat!");
  auto vis_img = im.clone();
  auto background_copy = background.clone();
  int height = im.rows;
  int width = im.cols;
  int bg_height = background.rows;
  int bg_width = background.cols;
  if ((vis_img).type() != CV_8UC3) {
    (vis_img).convertTo((vis_img), CV_8UC3);
  }
  if ((background_copy).type() != CV_8UC3) {
    (background_copy).convertTo((background_copy), CV_8UC3);
  }
  if ((bg_height != height) || (bg_width != width)) {
    cv::resize(background, background_copy, cv::Size(width, height));
  }
  uchar* vis_data = static_cast<uchar*>(vis_img.data);
  uchar* background_data = static_cast<uchar*>(background_copy.data);
  uchar* im_data = static_cast<uchar*>(im.data);
  float keep_value = 0.f;
  for (size_t i = 0; i < height; ++i) {
    for (size_t j = 0; j < width; ++j) {
      int category_id = result.label_map[i * width + j];
      if (background_label != category_id) {
        keep_value = 1.0f;
      } else {
        keep_value = 0.f;
      }
      for (size_t c = 0; c < 3; ++c) {
        vis_data[i * width * 3 + j * 3 + c] = cv::saturate_cast<uchar>(
            static_cast<float>(im_data[i * width * 3 + j * 3 + c]) *
                keep_value +
            (1.f - keep_value) * background_data[i * width * 3 + j * 3 + c]);
      }
    }
  }
  return vis_img;
}

}  // namespace vision
}  // namespace fastdeploy
#endif