Update to FLIP v1.7

.github/workflows/flip-deploy.yml

@@ -16,12 +16,11 @@ jobs:
   build_wheels:
     strategy:
       matrix:
-        # macos-13 is an intel runner, macos-14 is apple silicon
-        os: [ubuntu-latest, windows-latest, macos-13, macos-14]
+        os: [ubuntu-latest, windows-latest, macos-latest]
         python: [cp38, cp39, cp310, cp311, cp312, cp312_stable, cp313]
         exclude:
           # The first Python version to target Apple arm64 architectures is 3.9.
-          - os: macos-14
+          - os: [macos-latest]
             python: cp38
     name: >
       ${{ matrix.python }} wheel for ${{ matrix.os }}

MODULE.bazel

@@ -30,7 +30,29 @@
 # SPDX-License-Identifier: BSD-3-Clause
 #################################################################################
 
+<<<<<<<< HEAD:src/CMakeLists.txt
+cmake_minimum_required(VERSION 3.9)
+
+set(CMAKE_DISABLE_SOURCE_CHANGES ON)
+set(CMAKE_DISABLE_IN_SOURCE_BUILD ON)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
+set(CMAKE_BUILD_TYPE_INIT "Release")
+
+project(flip LANGUAGES CXX)
+
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR})
+include(GNUInstallDirs)
+
+option(FLIP_ENABLE_CUDA "Include CUDA version of flip" OFF)
+
+add_subdirectory(cpp)
+========
 module(
     name = "flip",
     compatibility_level = 1,
 )
+>>>>>>>> upstream/main:MODULE.bazel

README.md

@@ -1,6 +1,6 @@
 ![Teaser image](images/teaser.png "Teaser image")
 
-# FLIP: A Tool for Visualizing and Communicating Errors in Rendered Images (v1.6)
+# FLIP: A Tool for Visualizing and Communicating Errors in Rendered Images (v1.7)
 
 By
 [Pontus Ebelin](https://research.nvidia.com/person/pontus-ebelin)
@@ -27,6 +27,8 @@ The changes made for the different versions of FLIP are summarized in the [versi
 [An image gallery](https://research.nvidia.com/node/3525) displaying a large quantity of reference/test images and corresponding error maps from
 different metrics.
 
+**Note**: since v1.7, the automatic stop exposure in HDR-FLIP is able to handle reference images whose median luminance is 0.
+
 **Note**: since v1.6, the Python version of FLIP can now be installed via `pip install flip-evaluator`.
 
 **Note**: in v1.3, we switched to a *single header* ([FLIP.h](src/cpp/FLIP.h)) for C++/CUDA for easier integration.
@@ -136,4 +138,4 @@ Should your work use the FLIP tool in a more general fashion, please cite the Ra
 
 # Acknowledgements
 We appreciate the following peoples' contributions to this repository:
-Jonathan Granskog, Jacob Munkberg, Jon Hasselgren, Jefferson Amstutz, Alan Wolfe, Killian Herveau, Vinh Truong, Philippe Dagobert, Hannes Hergeth, Matt Pharr, Tizian Zeltner, Jan Honsbrok, Chris Zhang, Wenzel Jakob, and Julian Amann.
+Jonathan Granskog, Jacob Munkberg, Jon Hasselgren, Jefferson Amstutz, Alan Wolfe, Killian Herveau, Vinh Truong, Philippe Dagobert, Hannes Hergeth, Matt Pharr, Tizian Zeltner, Jan Honsbrok, Chris Zhang, Wenzel Jakob, Julian Amann, and Xijie Yang.

misc/versionList.md

@@ -3,6 +3,11 @@
 In addition to various minor changes, the following was
 changed for the different versions of FLIP:
 
+# Version 1.7 (commit ?)
+- Fixed memory leaks in the C++/CUDA/Python versions of FLIP.
+- HDR-FLIP: Fixed crashes that followed from the reference's median being 0.
+    - Automatic start and stop exposures in HDR-FLIP are computed using statistics of the reference image. For the stop exposure, we use the median luminance of the reference. When that is 0, we used to get undefined behavior or a crash. Version 1.7 fixes this by clamping the median to have a minimum value of [FLT_EPSILON](https://learn.microsoft.com/en-us/cpp/c-language/limits-on-floating-point-constants?view=msvc-170).
+
 # Version 1.6 (commit 7967578)
 - Flipped the ꟻ in ꟻLIP. The entire name (FLIP) should now be readable on all devices.
 - Published Python version of FLIP to PyPI (URL: https://pypi.org/project/flip-evaluator/).

pyproject.toml

@@ -1,5 +1,5 @@
 #################################################################################
-# Copyright (c) 2020-2024, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# Copyright (c) 2020-2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
@@ -26,7 +26,7 @@
 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #
-# SPDX-FileCopyrightText: Copyright (c) 2020-2024 NVIDIA CORPORATION & AFFILIATES
+# SPDX-FileCopyrightText: Copyright (c) 2020-2025 NVIDIA CORPORATION & AFFILIATES
 # SPDX-License-Identifier: BSD-3-Clause
 #################################################################################
 
@@ -36,7 +36,7 @@ build-backend = "scikit_build_core.build"
 
 [project]
 name = "flip_evaluator"
-version = "1.6.0.1"
+version = "1.7"
 description = "A Difference Evaluator for Alternating Images"
 readme = "README.md"
 requires-python = ">=3.8"

src/cpp/FLIP.h

@@ -2227,6 +2227,7 @@ namespace FLIP
             size_t medianLocation = luminances.size() / 2;
             std::nth_element(luminances.begin(), luminances.begin() + medianLocation, luminances.end());
             float Ymedian = luminances[medianLocation];
+            Ymedian = std::max(Ymedian, std::numeric_limits<float>::epsilon()); // Avoid median = 0 when more than half of the image's pixels are black.
 
             startExposure = log2(xMax / Ymax);
             stopExposure = log2(xMax / Ymedian);

src/cpp/README.md

@@ -1,4 +1,4 @@
-# FLIP: A Tool for Visualizing and Communicating Errors in Rendered Images (v1.6)
+# FLIP: A Tool for Visualizing and Communicating Errors in Rendered Images (v1.7)
 
 By
 [Pontus Ebelin](https://research.nvidia.com/person/pontus-ebelin)

src/cpp/tool/FLIPToolHelpers.h

@@ -480,7 +480,7 @@ namespace FLIPTool
 
         std::string FLIPString = "FLIP";
         int MajorVersion = 1;
-        int MinorVersion = 6;
+        int MinorVersion = 7;
 
         if (commandLine.optionSet("help"))
         {

src/cpp/tool/imagehelpers.h

@@ -255,6 +255,7 @@ namespace ImageHelpers
         if (loadImage(fileName, imgWidth, imgHeight, pixels))
         {
             dstImage.setPixels(pixels, imgWidth, imgHeight);
+            delete[] pixels;
             return true;
         }
         return false;
@@ -343,16 +344,15 @@ namespace ImageHelpers
 
         const char* error;
         int ret = SaveEXRImageToFile(&exrImage, &exrHeader, fileName.c_str(), &error);
+        free(exrHeader.channels);
+        free(exrHeader.pixel_types);
+        free(exrHeader.requested_pixel_types);
         if (ret != TINYEXR_SUCCESS)
         {
             std::cerr << "Failed to save EXR file <" << fileName << ">: " << error << "\n";
             return false;
         }
 
-        free(exrHeader.channels);
-        free(exrHeader.pixel_types);
-        free(exrHeader.requested_pixel_types);
-
         return true;
     }
 }

src/python/README.md

@@ -1,4 +1,4 @@
-# FLIP: A Tool for Visualizing and Communicating Errors in Rendered Images (v1.6)
+# FLIP: A Tool for Visualizing and Communicating Errors in Rendered Images (v1.7)
 
 By
 [Pontus Ebelin](https://research.nvidia.com/person/pontus-ebelin)

src/pytorch/README.md

@@ -1,4 +1,4 @@
-# FLIP: A Tool for Visualizing and Communicating Errors in Rendered Images (v1.6)
+# FLIP: A Tool for Visualizing and Communicating Errors in Rendered Images (v1.7)
 
 By
 [Pontus Ebelin](https://research.nvidia.com/person/pontus-ebelin)

src/pytorch/flip_loss.py

@@ -383,6 +383,7 @@ def compute_start_stop_exposures(reference, tone_mapper, tmax, tmin):
 	dim = Y_reference.size()
 	Y_ref = Y_reference.view(dim[0], dim[1], dim[2]*dim[3])
 	Y_lo = torch.median(Y_ref, dim=2).values.unsqueeze(2).unsqueeze(3)
+	Y_lo = torch.clamp(Y_lo, min=torch.finfo(torch.float32).eps) # Avoid median = 0 when more than half of the image's pixels are black.
 	stop_exposure = torch.log2(x_min / Y_lo)
 
 	return start_exposure, stop_exposure