ifm3d::Buffer Class Reference

The class Buffer represent a STL container to store data from the ifm devices in 2 dimension and supports multiple channel. More...

#include <ifm3d/fg/buffer.h>

Classes
struct	Iterator

Public Member Functions
	Buffer ()
	These are various constructors that form a Buffer. More...
	Buffer (const std::uint32_t cols, const std::uint32_t rows, const std::uint32_t nchannel, ifm3d::pixel_format format, std::optional< ifm3d::json > metadata=std::nullopt)
	Buffer (Buffer &&)=default
Buffer &	operator= (Buffer &&)=default
	Buffer (const Buffer &)=default
Buffer &	operator= (const Buffer &)=default
void	create (const std::uint32_t cols, const std::uint32_t rows, const std::uint32_t nchannel, ifm3d::pixel_format format)
Buffer	clone () const
	Creates a full copy of the array and the underlying data.
std::uint32_t	height () const
std::uint32_t	width () const
std::uint32_t	nchannels () const
ifm3d::pixel_format	dataFormat () const
ifm3d::json	metadata () const
size_t	size () const
	Return the size of the buffer in bytes.
template<typename T = std::uint8_t>
T *	ptr (const std::uint32_t row)
	returns a pointer to the specified Buffer row. More...
template<typename T = std::uint8_t>
T const *	ptr (const std::uint32_t row) const
	returns a pointer to the specified Buffer row. More...
template<typename T = std::uint8_t>
T *	ptr (const std::uint32_t row, const std::uint32_t col)
	Pointer to the Pixel at row,col. More...
template<typename T = std::uint8_t>
T const *	ptr (const std::uint32_t row, const std::uint32_t col) const
	Pointer to the Pixel at row,col. More...
template<typename T >
T &	at (const std::size_t index)
template<typename T >
T &	at (const std::uint32_t row, const std::uint32_t col)
template<typename T >
T const &	at (const std::size_t index) const
template<typename T >
T const &	at (const std::uint32_t row, const std::uint32_t col) const
template<typename T >
void	setTo (const T val, const ifm3d::Buffer &mask)
template<typename T >
Iterator< T >	begin ()
template<typename T >
Iterator< T >	end ()

Detailed Description

The class Buffer represent a STL container to store data from the ifm devices in 2 dimension and supports multiple channel.

Data stored in sequential memory layout and class provides function template to access the pixel. Creating an Buffer object :

• Use the Create(cols, rows, nchannel, ifm3d::pixel_format ) method or the similar Buffer(cols, rows, nchannel, type) constructor.

For example, FORMAT_8U means a 8-bit array, FORMAT_32F floating-point array, and so on.

//a 100 x 100 Buffer of type 8U
ifm3d::Buffer image(100,100,1,ifm3d::FORMAT_8U);
// and now turn image to a 10 x10 3-channel 8-bit matrix.
// The old content will be deallocated
image.create(10,10,3,ifm3d::FORMAT_8U);

note: create() allocates new memory.

• Accessing the pixels use at<T>(index) or at<T>(i,j) to access the pixel this return the reference to the pixel. A pixel is defined as structure of n-channel values at a given index or pixel position in 2D array

to access a pixel in Buffer I ( 100,100,1,ifm3d::FORMAT_8U) at 50,50 position

auto pixel = I<uint8_t>(50,50);
// if working as Index array then
 
auto index = 50*100 + 50 ;
auto pixel = I<uint8_t>(index);

changing the pixel value can be done as follow : writing 100 at pixel postion 50,50

I<uint8_t>(50,50) = 100;
I<uint8_t>(index) = 100;

to access a pixel in n-channel Buffer I ( 100,100,3,ifm3d::FORMAT_8U) at 50,50 position This will be the case accessing the values for 3 channel Buffer as pixel is structure of the values of n-chanel at given position.

auto pixel = I<Point3D<uint8_t>>(50,50);
 
//now individual channel values can be access with
val[0], val[1] , val[2]

• Processing the whole array If you need to process a whole image, the most efficient way is to get the pointer to the row first, and then just use the plain C operator[] :

  Buffer I(100,100,1,FORMAT_8U);
  for(int i = 0; i < I.height(); i++)
   {
    const uint8_t* rowi = M.ptr<uint8_t>(i);
    for(int j = 0; j < I.width(); j++)
     {
      //some operation here
     }
   }

One can also use range based for loops with adapter explained in ifm3d::IteratorAdapter section

Constructor & Destructor Documentation

Buffer()

ifm3d::Buffer::Buffer

(

)

These are various constructors that form a Buffer.

default constructor for forming a Buffer. User further needs to call create Method to actually allocates the memory

Member Function Documentation

ptr() [1/4]

template<typename T = std::uint8_t>

T* ifm3d::Buffer::ptr

(

const std::uint32_t

row

)

returns a pointer to the specified Buffer row.

Parameters

row

number

ptr() [2/4]

template<typename T = std::uint8_t>

T const* ifm3d::Buffer::ptr

(

const std::uint32_t

row

)

const

returns a pointer to the specified Buffer row.

Parameters

row

number

ptr() [3/4]

template<typename T = std::uint8_t>

T* ifm3d::Buffer::ptr	(	const std::uint32_t	row,
		const std::uint32_t	col
	)

Pointer to the Pixel at row,col.

Parameters

row	1st dimension index
col	2nd dimension index

ptr() [4/4]

template<typename T = std::uint8_t>

T const* ifm3d::Buffer::ptr	(	const std::uint32_t	row,
		const std::uint32_t	col
	)		const

Pointer to the Pixel at row,col.

Parameters

row	1st dimension index
col	2nd dimension index

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The documentation for this class was generated from the following file:

• ifm3d/fg/buffer.h