fix cropped export from preview (#125)

Author: krupkat

tests/stitcher_pipeline_test.cc

@@ -26,6 +26,8 @@
 #include "xpano/algorithm/options.h"
 #include "xpano/algorithm/stitcher.h"
 #include "xpano/constants.h"
+#include "xpano/utils/rect.h"
+#include "xpano/utils/vec_opencv.h"
 
 using Catch::Matchers::Equals;
 using Catch::Matchers::WithinAbs;
@@ -441,6 +443,46 @@ TEST_CASE("Export [extra results]") {
   std::filesystem::remove(tmp_path);
 }
 
+TEST_CASE("Export with crop") {
+  const std::filesystem::path tmp_path =
+      xpano::tests::TmpPath().replace_extension("png");
+
+  xpano::pipeline::StitcherPipeline<kReturnFuture> stitcher;
+  auto loading_task = stitcher.RunLoading(kInputsWithExifMetadata, {}, {});
+  auto data = loading_task.future.get();
+  REQUIRE(data.panos.size() == 1);
+
+  auto crop = xpano::utils::Rect(xpano::utils::Ratio2f{0.25f, 0.25f},
+                                 xpano::utils::Ratio2f{0.5f, 0.75f});
+  auto stitch_result = stitcher
+                           .RunStitching(data, {.pano_id = 0,
+                                                .export_path = tmp_path,
+                                                .export_crop = crop})
+                           .future.get();
+
+  const float eps = 0.02;
+
+  CHECK(stitch_result.pano.has_value());
+  CHECK(stitch_result.export_path.has_value());
+
+  REQUIRE(std::filesystem::exists(tmp_path));
+  auto image = cv::imread(tmp_path.string());
+  REQUIRE(!image.empty());
+  CHECK_THAT(image.rows, WithinRel(488, eps));
+  CHECK_THAT(image.cols, WithinRel(334, eps));
+
+  auto cv_rect = xpano::utils::GetCvRect(*stitch_result.pano, crop);
+  auto pano_cropped = (*stitch_result.pano)(cv_rect);
+
+  REQUIRE(pano_cropped.rows == image.rows);
+  REQUIRE(pano_cropped.cols == image.cols);
+
+  auto avg_diff = cv::norm(pano_cropped, image);
+  CHECK(avg_diff <= 1e-6);
+
+  std::filesystem::remove(tmp_path);
+}
+
 TEST_CASE("ExportWithMetadata") {
   const std::filesystem::path tmp_path =
       xpano::tests::TmpPath().replace_extension("jpg");

xpano/gui/pano_gui.cc

@@ -586,12 +586,12 @@ void PanoGui::PerformExportAction(int pano_id) {
     return;
   }
 
+  const auto& pano = stitcher_data_->panos.at(pano_id);
   if (plot_pane_.Type() == ImageType::kPanoFullRes) {
     std::optional<std::filesystem::path> metadata_path;
     if (options_.metadata.copy_from_first_image) {
       metadata_path = first_image->GetPath();
     }
-    const auto& pano = stitcher_data_->panos.at(pano_id);
     stitcher_pipeline_.RunExport(plot_pane_.Image(),
                                  {.pano_id = pano_id,
                                   .export_path = *export_path,
@@ -603,6 +603,7 @@ void PanoGui::PerformExportAction(int pano_id) {
                                     {.pano_id = pano_id,
                                      .full_res = true,
                                      .export_path = *export_path,
+                                     .export_crop = pano.crop,
                                      .metadata = options_.metadata,
                                      .compression = options_.compression,
                                      .stitch_algorithm = options_.stitch});

xpano/pipeline/stitcher_pipeline.cc

@@ -257,7 +257,8 @@ StitchingResult RunStitchingPipeline(
     export_path = RunExportPipeline(result,
                                     {.export_path = *options.export_path,
                                      .metadata_path = metadata_path,
-                                     .compression = options.compression},
+                                     .compression = options.compression,
+                                     .crop = options.export_crop},
                                     progress)
                       .export_path;
   }

xpano/pipeline/stitcher_pipeline.h

@@ -31,6 +31,7 @@ struct StitchingOptions {
   int pano_id = 0;
   bool full_res = false;
   std::optional<std::filesystem::path> export_path;
+  std::optional<utils::RectRRf> export_crop;
   MetadataOptions metadata;
   CompressionOptions compression;
   StitchAlgorithmOptions stitch_algorithm;

xpano/utils/vec_opencv.h

@@ -5,6 +5,7 @@
 
 #include <opencv2/core.hpp>
 
+#include "xpano/utils/rect.h"
 #include "xpano/utils/vec.h"
 
 namespace xpano::utils {