This makes it possible to compile OpenCV with for instance ndk-r16

* Load and save tiff images in CV_32FC1 format (1 channel of floats).

* Add test

* Fix error handling and resources leak. Improve test.

Signed-off-by: Li Peng <peng.li@intel.com>

Signed-off-by: Li Peng <peng.li@intel.com>

* add style draw in yolo

* fix sintaxe whitespace

* fix conversion from float to int

* sample refactoring

- minor code style fixes
- avoid confusing "bottom" names
- use cv::format
- always draw object detection/roi

Updating stiching.cpp to resolve new line issue #10461 (#10469)

Updating the documentation of the rotcalipers.cpp to resolve issue #10096

* added write as pbm

* add tests for pbm

* imgcodecs: PBM support

- drop additional PBM parameters
- write: fix P1/P4 mode (no maxval 255 value after width/height)
- write: invert values for P1/P4
- write: P1: compact ASCII mode (no spaces)
- simplify pbm test
- drop .pxm extension (http://netpbm.sourceforge.net/doc/ doesn't know such extension)

Hough many circles (#10232)

* Add Hui's optimization. Merge with latest changes in OpenCV.

* Use conditional compilation instead of a runtime flag.

* Whitespace.

* Create the sequence for the nonzero edge pixels only if using that approach.

* Improve performance for finding very large numbers of circles

* Return the circles with the larger accumulator values first, as per API documentation.
Use a separate step to check distance between circles. Allows circles to be sorted by strength first. Avoids locking in EstimateRadius which was slowing it down.
Return centers only if maxRadius == 0 as per API documentation.

* Sort the circles so results are deterministic. Otherwise the order of circles with the same strength depends on parallel processing completion order.

* Add test for HoughCircles.

* Add beads test.

* Wrap the non-zero points structure in a common interface so the code can use either a vector or a matrix.

* Remove the special case for skipping the radius search if maxRadius==0.

* Add performance tests.

* Use NULL instead of nullptr.
OpenCV should compile with C++98 compiler.

* Put test suite name first.
Use different test suite names for each test to avoid an error from the test runner.

* Address build bot errors and warnings.

* Skip radius search if maxRadius < 0.

* Dynamically switch to NZPointList when it will be faster than NZPointSet.

* Fix compile error: missing 'typename' prior to dependent type name.

* Fix compile error: missing 'typename' prior to dependent type name.
This time fix it the non C++ 11 way.

* Fix compile error: no type named 'const_reference' in 'class cv::NZPointList'

* Disable ManySmallCircles tests. Failing on Mac.

* Change beads image to JPEG for smaller file size.
Try enabling the ManySmallCircles tests again.

* Remove ManySmallCircles tests. They are failing on the Mac build.

* Fix expectations to check all circles.

* Changing case on a case-insensitive file system
Step 1: remove the old file names

* Changing case on a case-insensitive file system
Step 2: add them back with the new names

* Fix cmpAccum function to be strictly weak ordered.

* Add tests for many small circles.

* imgproc(perf): fix HoughCircles tests

* imgproc(houghCircles): refactor code

- simplify NZPointList
- drop broken (de-synchronization of 'current'/'mi' fields) NZPointSet iterator
- NZPointSet iterator is replaced to direct area scan
- use SIMD intrinsics
- avoid std exceptions (build for embedded systems)

Add a flag to disable memory reusing in dnn module.