Add a warning message using CV_LOG__WARNING().
This way api behaviour is preserved. Outputs are
the same but user gets an extra warning in case
fopen() fails to access image file for some reason.
This would help new users and also debugging
complex apps which use imread()
Signed-off-by: Nnickjackolson <metedurlu@gmail.com>

Documentation was desynchronized in commit 11eafca3

Add reading of specific images from multipage tiff

* Add reading of specific images from multipage tiff

* Fix build issues

* Add missing flag for gdal

* Fix unused param warning

* Remove duplicated code

* change public parameter type to int

* Fix warnings

* Fix parameter check

Exif parsing for PNG files to support Exif orientation tag.  Moved decoder specific Exif parsing to JPEG and PNG decoders, respectively. Issue 16579

Fix cvSaveImage( ) function bug

* fix cvSaveImage crash

* replace emplace_back with {}, no C++11 required

* fix MacOSX build with vector's push_back

* OpenJPEG: decoder for J2K codestreams

* code review fixes

* exclude .j2c from GDAL tests

Jpeg2000 OpenJPEG port

* OpenJPEG based JPEG2000 decoder implementation

Currently, the following input color spaces and depth conversions are
supported:

- 8 bit -> 8 bit
- 16 bit -> 16 bit (IMREAD_UNCHANGED, IMREAD_ANYDEPTH)

- RGB(a) -> BGR
- RGBA -> BGRA (IMREAD_UNCHANGED)
- Y(a) -> Y(a) (IMREAD_ANYCOLOR, IMREAD_GRAY, IMREAD_UNCHANGED))
- YCC -> Y (IMREAD_GRAY)

* Check for OpenJPEG availability

This enables OpenJPEG based JPEG2000 imread support by default, which
can be disabled by -DWITH_OPENJPEG=OFF. In case OpenJPEG is enabled
and found, any checks for Jasper are skipped.

* Implement precision downscaling for precision > 8 without IMREAD_UNCHANGED

With IMREAD_UNCHANGED, values are kept from the input image, without it
components are downscaled to CV_8U range.

* Enable Jpeg2K tests when OpenJPEG is available

* Add support for some more color conversions

Support IMREAD_GRAY when input color space is RGB or unspecified.
Support YUV input color space for BGR output.

* fix: problems with unmanaged memory

* fix: CMake warning - HAVE_OPENJPEG is undefined

Removed trailing whitespaces

* fix: CMake find_package OpenJPEG add minimal version

* Basic JPEG2K encoder

Images with depth CV_8U and CV_16U are supported, with 1 to 4 channels.

* feature: Improved code for OpenJPEG2000 encoder/decoder

 - Removed code duplication
 - Added error handlers
 - Extracted functions

* feature: Update conversion openjpeg array from/to Mat

* feature: Extend ChannelsIterator to fulfill RandomAccessIterator named requirements

 - Removed channels split in copyFromMatImpl. With ChannelsIterator no allocations are performed.
 - Split whole loop into 2 parts in copyToMat -> where std::copy and std::transforms are called.

* fix: Applied review comments.

 - Changed `nullptr` in CV_LOG* functions to `NULL`
 - Added `falls through` comment in decoder color space `switch`
 - Added warning about unsupported parameters for the encoder

* feature: Added decode from in-memory buffers.
Co-authored-by: NVadim Levin <vadim.levin@xperience.ai>

If applied, this commit will describe permission denied message in imwrite_ function when user does not have write permission

* Added flag handlers for imread and imdecode | Issue 16203

Undo imread change

Added Imread resize tests

Added imdecode flags check

Added imdecode tests for resize

Removed trailing whitespace

Removed IMREAD_IGNORE_ORIENTATION check

Added else condition

Removed IMREAD_IGNORE_ORIENTATION check in decode

Added HAVE_JPEG guards

Added static_cast for Win32

Added resize for non jpegs

Added tests for non jpeg resize case

Fixed resize value in assert

Changed tests to Value-Parameterized Tests

Changed tests to Value-Parameterized Tests | handled >> in cpp

Changed tests to Value-Parameterized Tests | removed trailing whitespace

* imgcodecs: update test

OpenCV upstream stuff may reinterpret vector as column.

* try to solve #13381

* Add note

* removed C API in the following modules: photo, video, imgcodecs, videoio

* trying to fix various compile errors and warnings on Windows and Linux

* continue to fix compile errors and warnings

* continue to fix compile errors, warnings, as well as the test failures

* trying to resolve compile warnings on Android

* Update cap_dc1394_v2.cpp

fix warning from the new GCC

This reverts commit 7349b8f5 (partially).

- don't reallocate passed 'img' (test fixed - must use IMREAD_UNCHANGED / IMREAD_ANYCOLOR)
- avoid memory DDOS
- avoid reading of whole file during header processing
- avoid data access after allocated buffer during header processing (missing checks)
- use WebPFree() to free allocated buffers (libwebp >= 0.5.0)
- drop unused & undefined `.close()` method
- added checks for channels >= 5 in encoder

* created new decoder and encoder for PFM

pfm file format stores binary RGB or grayscale float images.

* added test for pfm codec

* replaced large with short licence header

* little/big-endian-check is now compile time

* fixed width/height confusion, improved big/little endian recognition, fixed scaling issue and Improved signature check

* adapted tests to handle float images well

* removed data-dependency: lena.pfm

the lena image is now loaded is pam and converted to pfm.

* fixed bug in endianess detection macro

* Added endianess detection for android and win

* removed fancy endianess detection

endianess detection will be implemented in cmake scripts soonish.

* fixed minor warnings

* fixed stupid elif defined bug

* silenced some implicit cast warnings

* replaced std::to_string with std::stringstream solution

std::to_string variant did not build on android.

* replaced new endianess macros with existing ones

* improved readability

* imgcodecs cmake: the option to customize supported formats list (WITH_IMGCODEC_HDR, WITH_IMGCODEC_SUNRASTER, WITH_IMGCODEC_PXM)

* imgcodecs: fixes

- fixed CMake scripts (=OFF doesn't really work)
- restore dropped GDCM block
- added _IMGCODEC_ prefix
- fixed tests
- include PAM format under WITH_IMGCODEC_PXM option

* fix cv::imwrite to allow cv::UMat and vectors of it to be written

* cv::imwrite failure handling improvements

* Unit test for regression testing imwrite support for and fix whitespace

* 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)

Implementation of bit-exact resize. Internal calls to linear resize updated to use bit-exact version. (#9468)

Drop code under *undefined* HAVE_TIFF
(violates several policies, like a way to turn off tiff support)

Previously, the return value of fwrite and fclose were not properly
checked, leading to possible silent truncation of the data if writing
failed, e.g. due to lack of disk space.

Fixes issue #9251.

autorotate in-memory jpegs (#8492)

* autorotate in-memory jpegs

* correct indentation (4 spaces)

* imgcodecs: don't apply EXIF rotation for unloaded images

* videoio: don't try to rotate MJPEG stream

* imgcodecs: ByteStreamBuffer::seekoff support all seek "dir"

* imgcodecs: fix condition: "off == egptr() - eback()" is valid offset