I give up now!
I installed Ubuntu 20.10 in Virtualbox, download the latest git code, ran a build (only inlcuded samples to be built - everything else the default build) and executed the sample code again, and I still get the error that it cannot read the jpg or png files I give it.
My version_string is:
“\n”
“General configuration for OpenCV 4.5.1-dev =====================================\n”
" Version control: 4.5.1-35-gbec7b297ed\n"
“\n”
" Platform:\n"
" Timestamp: 2020-12-30T22:13:36Z\n"
" Host: Linux 5.8.0-33-generic x86_64\n"
" CMake: 3.16.3\n"
" CMake generator: Unix Makefiles\n"
" CMake build tool: /usr/bin/gmake\n"
" Configuration: Release\n"
“\n”
" CPU/HW features:\n"
" Baseline: SSE SSE2 SSE3\n"
" requested: SSE3\n"
" Dispatched code generation: SSE4_1 SSE4_2 FP16 AVX AVX2 AVX512_SKX\n"
" requested: SSE4_1 SSE4_2 AVX FP16 AVX2 AVX512_SKX\n"
" SSE4_1 (17 files): + SSSE3 SSE4_1\n"
" SSE4_2 (2 files): + SSSE3 SSE4_1 POPCNT SSE4_2\n"
" FP16 (1 files): + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 AVX\n"
" AVX (5 files): + SSSE3 SSE4_1 POPCNT SSE4_2 AVX\n"
" AVX2 (31 files): + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 FMA3 AVX AVX2\n"
" AVX512_SKX (7 files): + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 FMA3 AVX AVX2 AVX_512F AVX512_COMMON AVX512_
SKX\n"
“\n”
" C/C++:\n"
" Built as dynamic libs?: YES\n"
" C++ standard: 11\n"
" C++ Compiler: /usr/bin/c++ (ver 10.2.0)\n"
" C++ flags (Release): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=ad
dress -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpoint
er-arith -Wshadow -Wsign-promo -Wuninitialized -Wsuggest-override -Wno-delete-non-virtual-dtor -Wno-comment -Wim
plicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer
-ffunction-sections -fdata-sections -msse -msse2 -msse3 -fvisibility=hidden -fvisibility-inlines-hidden -O3 -D
NDEBUG -DNDEBUG\n"
" C++ flags (Debug): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=ad
dress -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpoint
er-arith -Wshadow -Wsign-promo -Wuninitialized -Wsuggest-override -Wno-delete-non-virtual-dtor -Wno-comment -Wim
plicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer
-ffunction-sections -fdata-sections -msse -msse2 -msse3 -fvisibility=hidden -fvisibility-inlines-hidden -g -O
0 -DDEBUG -D_DEBUG\n"
" C Compiler: /usr/bin/cc\n"
" C flags (Release): -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-po
int -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Wi
nit-self -Wpointer-arith -Wshadow -Wuninitialized -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fd
iagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -msse -
msse2 -msse3 -fvisibility=hidden -O3 -DNDEBUG -DNDEBUG\n"
" C flags (Debug): -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-po
int -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Wi
nit-self -Wpointer-arith -Wshadow -Wuninitialized -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fd
iagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -msse -
msse2 -msse3 -fvisibility=hidden -g -O0 -DDEBUG -D_DEBUG\n"
" Linker flags (Release): -Wl,–exclude-libs,libippicv.a -Wl,–exclude-libs,libippiw.a -Wl,–gc-sectio
ns -Wl,–as-needed \n"
" Linker flags (Debug): -Wl,–exclude-libs,libippicv.a -Wl,–exclude-libs,libippiw.a -Wl,–gc-sectio
ns -Wl,–as-needed \n"
" ccache: NO\n"
" Precompiled headers: NO\n"
" Extra dependencies: dl m pthread rt\n"
" 3rdparty dependencies:\n"
“\n”
" OpenCV modules:\n"
" To be built: calib3d core dnn features2d flann gapi highgui imgcodecs imgproc ml objdetect
photo stitching ts video videoio\n"
" Disabled: world\n"
" Disabled by dependency: -\n"
" Unavailable: java python2 python3\n"
" Applications: tests perf_tests examples apps\n"
" Documentation: NO\n"
" Non-free algorithms: NO\n"
“\n”
" GUI: \n"
" GTK+: NO\n"
" VTK support: NO\n"
“\n”
" Media I/O: \n"
" ZLib: zlib (ver 1.2.11)\n"
" JPEG: libjpeg-turbo (ver 2.0.6-62)\n"
" WEBP: build (ver encoder: 0x020f)\n"
" PNG: build (ver 1.6.37)\n"
" TIFF: build (ver 42 - 4.0.10)\n"
" JPEG 2000: build (ver 2.3.1)\n"
" OpenEXR: build (ver 2.3.0)\n"
" HDR: YES\n"
" SUNRASTER: YES\n"
" PXM: YES\n"
" PFM: YES\n"
“\n”
" Video I/O:\n"
" DC1394: NO\n"
" FFMPEG: NO\n"
" avcodec: NO\n"
" avformat: NO\n"
" avutil: NO\n"
" swscale: NO\n"
" avresample: NO\n"
" GStreamer: NO\n"
" v4l/v4l2: YES (linux/videodev2.h)\n"
“\n”
" Parallel framework: pthreads\n"
“\n”
" Trace: YES (with Intel ITT)\n"
“\n”
" Other third-party libraries:\n"
" Intel IPP: 2020.0.0 Gold [2020.0.0]\n"
" at: /home/name/git/opencv/build/3rdparty/ippicv/ippicv_lnx/icv\n"
" Intel IPP IW: sources (2020.0.0)\n"
" at: /home/name/git/opencv/build/3rdparty/ippicv/ippicv_lnx/iw\n"
" Lapack: NO\n"
" Eigen: NO\n"
" Custom HAL: NO\n"
" Protobuf: build (3.5.1)\n"
“\n”
" OpenCL: YES (no extra features)\n"
" Include path: /home/name/git/opencv/3rdparty/include/opencl/1.2\n"
" Link libraries: Dynamic load\n"
“\n”
" Python (for build): /usr/bin/python3\n"
“\n”
" Java: \n"
" ant: NO\n"
" JNI: NO\n"
" Java wrappers: NO\n"
" Java tests: NO\n"
“\n”
" Install to: /usr/local\n"
“-----------------------------------------------------------------\n”
“\n”