Mat Class Reference

The Mat class can handle multiple matrix format from 1 to 4 channels, with different value types (float or uchar), and can be stored CPU and/or GPU side. More...

General Functions

 Mat ()
 empty Mat default constructor. More...
 
 Mat (size_t width, size_t height, MAT_TYPE mat_type, MEM memory_type=MEM_CPU)
 Mat constructor. More...
 
 Mat (size_t width, size_t height, MAT_TYPE mat_type, sl::uchar1 *ptr, size_t step, MEM memory_type=MEM_CPU)
 Mat constructor from an existing data pointer. More...
 
 Mat (size_t width, size_t height, MAT_TYPE mat_type, sl::uchar1 *ptr_cpu, size_t step_cpu, sl::uchar1 *ptr_gpu, size_t step_gpu)
 Mat constructor from two existing data pointers, CPU and GPU. More...
 
 Mat (Resolution resolution, MAT_TYPE mat_type, MEM memory_type=MEM_CPU)
 Mat constructor. More...
 
 Mat (Resolution resolution, MAT_TYPE mat_type, sl::uchar1 *ptr, size_t step, MEM memory_type=MEM_CPU)
 Mat constructor from an existing data pointer. More...
 
 Mat (Resolution resolution, MAT_TYPE mat_type, sl::uchar1 *ptr_cpu, size_t step_cpu, sl::uchar1 *ptr_gpu, size_t step_gpu)
 Mat constructor from two existing data pointers, CPU and GPU. More...
 
 Mat (const Mat &mat)
 Mat constructor by copy (shallow copy). More...
 
void alloc (size_t width, size_t height, MAT_TYPE mat_type, MEM memory_type=MEM_CPU)
 Allocates the Mat memory. More...
 
void alloc (Resolution resolution, MAT_TYPE mat_type, MEM memory_type=MEM_CPU)
 Allocates the Mat memory. More...
 
 ~Mat ()
 Mat destructor. This function calls free to release owned memory. More...
 
void free (MEM memory_type=MEM_CPU|MEM_GPU)
 Free the owned memory. More...
 
Matoperator= (const Mat &that)
 Performs a shallow copy. More...
 
ERROR_CODE updateCPUfromGPU ()
 Downloads data from DEVICE (GPU) to HOST (CPU), if possible. More...
 
ERROR_CODE updateGPUfromCPU ()
 Uploads data from HOST (CPU) to DEVICE (GPU), if possible. More...
 
ERROR_CODE copyTo (Mat &dst, COPY_TYPE cpyType=COPY_TYPE_CPU_CPU) const
 Copies data an other Mat (deep copy). More...
 
ERROR_CODE setFrom (const Mat &src, COPY_TYPE cpyType=COPY_TYPE_CPU_CPU, cudaStream_t stream=0)
 Copies data from an other Mat (deep copy). More...
 
ERROR_CODE read (const String &filePath)
 Reads an image from a file (only if MEM_CPU is available on the current Mat). More...
 
ERROR_CODE write (const String &filePath)
 Writes the Mat (only if MEM_CPU is available) into a file as an image. More...
 
template<typename T >
ERROR_CODE setTo (T value, MEM memory_type=MEM_CPU)
 Fills the Mat with the given value. More...
 
template<typename N >
ERROR_CODE setValue (size_t x, size_t y, N value, MEM memory_type=MEM_CPU)
 Sets a value to a specific point in the matrix. More...
 
template<typename N >
ERROR_CODE getValue (size_t x, size_t y, N *value, MEM memory_type=MEM_CPU) const
 Returns the value of a specific point in the matrix. More...
 
size_t getWidth () const
 Returns the width of the matrix. More...
 
size_t getHeight () const
 Returns the height of the matrix. More...
 
Resolution getResolution () const
 Returns the height of the matrix. More...
 
size_t getChannels () const
 Returns the number of values stored in one pixel. More...
 
MAT_TYPE getDataType () const
 Returns the format of the matrix. More...
 
MEM getMemoryType () const
 Returns the type of memory (CPU and/or GPU). More...
 
template<typename N >
N * getPtr (MEM memory_type=MEM_CPU) const
 Returns the CPU or GPU data pointer. More...
 
size_t getStepBytes (MEM memory_type=MEM_CPU) const
 Returns the memory step in Bytes (the Bytes size of one pixel row). More...
 
template<typename N >
size_t getStep (MEM memory_type=MEM_CPU) const
 Returns the memory step in number of elements (the number of values in one pixel row). More...
 
size_t getStep (MEM memory_type=MEM_CPU) const
 Returns the memory step in number of elements (the number of values in one pixel row). More...
 
size_t getPixelBytes () const
 Returns the size in bytes of one pixel. More...
 
size_t getWidthBytes () const
 Returns the size in bytes of a row. More...
 
String getInfos ()
 Return the informations about the Mat into a String. More...
 
bool isInit () const
 Defines whether the Mat is initialized or not. More...
 
bool isMemoryOwner () const
 Returns whether the Mat is the owner of the memory it access. More...
 
ERROR_CODE clone (const Mat &src)
 Duplicates Mat by copy (deep copy). More...
 
ERROR_CODE move (Mat &dst)
 Moves Mat data to another Mat. More...
 

Static Functions

static void swap (Mat &mat1, Mat &mat2)
 Swaps the content of the provided Mat (only swaps the pointers, no data copy). More...
 

Attributes

String name
 
bool verbose = false
 
timeStamp timestamp = 0
 

Detailed Description

The Mat class can handle multiple matrix format from 1 to 4 channels, with different value types (float or uchar), and can be stored CPU and/or GPU side.

Mat is defined in a row-major order, it means that, for an image buffer, the entire first row is stored first, followed by the entire second row, and so on.

The CPU and GPU buffer aren't automatically synchronized for performance reasons, you can use updateCPUfromGPU / updateGPUfromCPU to do it. If you are using the GPU side of the Mat object, you need to make sure to call free before destroying the sl::Camera object. The destruction of the sl::Camera object delete the CUDA context needed to free the GPU Mat memory.

Constructor and Destructor

Mat ( )

empty Mat default constructor.

Mat ( size_t  width,
size_t  height,
MAT_TYPE  mat_type,
MEM  memory_type = MEM_CPU 
)

Mat constructor.

This function directly allocates the requested memory. It calls alloc.

Parameters
width: width of the matrix in pixels.
height: height of the matrix in pixels.
mat_type: the type of the matrix (MAT_TYPE_32F_C1, MAT_TYPE_8U_C4...).
memory_type: defines where the buffer will be stored. (MEM_CPU and/or MEM_GPU).
Mat ( size_t  width,
size_t  height,
MAT_TYPE  mat_type,
sl::uchar1 ptr,
size_t  step,
MEM  memory_type = MEM_CPU 
)

Mat constructor from an existing data pointer.

This function doesn't allocate the memory.

Parameters
width: width of the matrix in pixels.
height: height of the matrix in pixels.
mat_type: the type of the matrix (MAT_TYPE_32F_C1, MAT_TYPE_8U_C4...).
ptr: pointer to the data array. (CPU or GPU).
step: step of the data array. (the Bytes size of one pixel row).
memory_type: defines where the buffer will be stored. (MEM_CPU and/or MEM_GPU).
Mat ( size_t  width,
size_t  height,
MAT_TYPE  mat_type,
sl::uchar1 ptr_cpu,
size_t  step_cpu,
sl::uchar1 ptr_gpu,
size_t  step_gpu 
)

Mat constructor from two existing data pointers, CPU and GPU.

This function doesn't allocate the memory.

Parameters
width: width of the matrix in pixels.
height: height of the matrix in pixels.
mat_type: the type of the matrix (MAT_TYPE_32F_C1, MAT_TYPE_8U_C4...).
ptr_cpu: CPU pointer to the data array.
step_cpu: step of the CPU data array (the Bytes size of one pixel row).
ptr_gpu: GPU pointer to the data array.
step_gpu: step of the GPU data array (the Bytes size of one pixel row).
Mat ( Resolution  resolution,
MAT_TYPE  mat_type,
MEM  memory_type = MEM_CPU 
)

Mat constructor.

This function directly allocates the requested memory. It calls alloc.

Parameters
resolution: the size of the matrix in pixels.
mat_type: the type of the matrix (MAT_TYPE_32F_C1, MAT_TYPE_8U_C4...).
memory_type: defines where the buffer will be stored (MEM_CPU and/or MEM_GPU).
Mat ( Resolution  resolution,
MAT_TYPE  mat_type,
sl::uchar1 ptr,
size_t  step,
MEM  memory_type = MEM_CPU 
)

Mat constructor from an existing data pointer.

This function doesn't allocate the memory.

Parameters
resolution: the size of the matrix in pixels.
mat_type: the type of the matrix (MAT_TYPE_32F_C1, MAT_TYPE_8U_C4...).
ptr: pointer to the data array. (CPU or GPU).
step: step of the data array (the Bytes size of one pixel row).
memory_type: defines where the buffer will be stored. (MEM_CPU and/or MEM_GPU).
Mat ( Resolution  resolution,
MAT_TYPE  mat_type,
sl::uchar1 ptr_cpu,
size_t  step_cpu,
sl::uchar1 ptr_gpu,
size_t  step_gpu 
)

Mat constructor from two existing data pointers, CPU and GPU.

This function doesn't allocate the memory.

Parameters
resolution: the size of the matrix in pixels.
mat_type: the type of the matrix (MAT_TYPE_32F_C1, MAT_TYPE_8U_C4...).
ptr_cpu: CPU pointer to the data array.
step_cpu: step of the CPU data array (the Bytes size of one pixel row).
ptr_gpu: GPU pointer to the data array.
step_gpu: step of the GPU data array (the Bytes size of one pixel row).
Mat ( const Mat mat)

Mat constructor by copy (shallow copy).

This function doesn't allocate the memory.

Parameters
mat: the reference to the Mat to copy.
~Mat ( )

Mat destructor. This function calls free to release owned memory.

Functions

void alloc ( size_t  width,
size_t  height,
MAT_TYPE  mat_type,
MEM  memory_type = MEM_CPU 
)

Allocates the Mat memory.

Parameters
width: width of the matrix in pixels.
height: height of the matrix in pixels.
mat_type: the type of the matrix (MAT_TYPE_32F_C1, MAT_TYPE_8U_C4...).
memory_type: defines where the buffer will be stored. (MEM_CPU and/or MEM_GPU).
Warning
It erases previously allocated memory.
void alloc ( Resolution  resolution,
MAT_TYPE  mat_type,
MEM  memory_type = MEM_CPU 
)

Allocates the Mat memory.

Parameters
resolution: the size of the matrix in pixels.
mat_type: the type of the matrix (sl::MAT_TYPE_32F_C1,sl::MAT_TYPE_8U_C4...).
memory_type: defines where the buffer will be stored. (sl::MEM_CPU and/or sl::MEM_GPU).
Warning
It erases previously allocated memory.
void free ( MEM  memory_type = MEM_CPU|MEM_GPU)

Free the owned memory.

Parameters
memory_type: specify whether you want to free the MEM_CPU and/or MEM_GPU memory.
Mat& operator= ( const Mat that)

Performs a shallow copy.

This function doesn't copy the data array, it only copies the pointer.

Parameters
that: the Mat to be copied.
Returns
The new Mat object which point to the same data as that.
ERROR_CODE updateCPUfromGPU ( )

Downloads data from DEVICE (GPU) to HOST (CPU), if possible.

Returns
SUCCESS if everything went well, ERROR_CODE_FAILURE otherwise.
Note
If no CPU or GPU memory are available for this Mat, some are directly allocated.
If verbose sets, you have informations in case of failure.
ERROR_CODE updateGPUfromCPU ( )

Uploads data from HOST (CPU) to DEVICE (GPU), if possible.

Returns
SUCCESS if everything went well, ERROR_CODE_FAILURE otherwise.
Note
If no CPU or GPU memory are available for this Mat, some are directly allocated.
If verbose sets, you have informations in case of failure.
ERROR_CODE copyTo ( Mat dst,
COPY_TYPE  cpyType = COPY_TYPE_CPU_CPU 
) const

Copies data an other Mat (deep copy).

Parameters
dst: the Mat where the data will be copied.
cpyType: specify the memories that will be used for the copy.
Returns
SUCCESS if everything went well, ERROR_CODE_FAILURE otherwise.
Note
If the destination is not allocated or has a not a compatible MAT_TYPE or Resolution, current memory is freed and new memory is directly allocated.
ERROR_CODE setFrom ( const Mat src,
COPY_TYPE  cpyType = COPY_TYPE_CPU_CPU,
cudaStream_t  stream = 0 
)

Copies data from an other Mat (deep copy).

Parameters
src: the Mat where the data will be copied from.
cpyType: specify the memories that will be used for the update.
Returns
SUCCESS if everything went well, ERROR_CODE_FAILURE otherwise.
Note
If the current Mat is not allocated or has a not a compatible MAT_TYPE or Resolution with the source, current memory is freed and new memory is directly allocated.
ERROR_CODE read ( const String filePath)

Reads an image from a file (only if MEM_CPU is available on the current Mat).

Supported input files format are PNG and JPEG.

Parameters
filePath: file path including the name and extension.
Returns
UCCESS if everything went well, ERROR_CODE_FAILURE otherwise.
Note
Supported MAT_TYPE are : MAT_TYPE_8U_C1, MAT_TYPE_8U_C3 and MAT_TYPE_8U_C4.
ERROR_CODE write ( const String filePath)

Writes the Mat (only if MEM_CPU is available) into a file as an image.

Supported output files format are PNG and JPEG.

Parameters
filePath: file path including the name and extension.
Returns
SUCCESS if everything went well, ERROR_CODE_FAILURE otherwise.
Note
Supported MAT_TYPE are : MAT_TYPE_8U_C1, MAT_TYPE_8U_C3 and MAT_TYPE_8U_C4.
ERROR_CODE setTo ( value,
MEM  memory_type = MEM_CPU 
)

Fills the Mat with the given value.

This function overwrite all the matrix.

Parameters
value: the value to be copied all over the matrix.
memory_type: defines which buffer to fill, CPU and/or GPU.
Note
This function is templated for uchar1, uchar2, uchar3, uchar4, float1, float2, float3, float4.
ERROR_CODE setValue ( size_t  x,
size_t  y,
value,
MEM  memory_type = MEM_CPU 
)

Sets a value to a specific point in the matrix.

Parameters
x: specify the column.
y: specify the row.
value: the value to be set.
memory_type: defines which memory will be updated.
Returns
SUCCESS if everything went well, ERROR_CODE_FAILURE otherwise.
Note
This function is templated for uchar1, uchar2, uchar3, uchar4, float1, float2, float3, float4.
Warning
Not efficient for MEM_GPU, use it on sparse data.
ERROR_CODE getValue ( size_t  x,
size_t  y,
N *  value,
MEM  memory_type = MEM_CPU 
) const

Returns the value of a specific point in the matrix.

Parameters
x: specify the column
y: specify the row
memory_type: defines which memory should be read.
Returns
SUCCESS if everything went well, ERROR_CODE_FAILURE otherwise.
Note
This function is templated for uchar1, uchar2, uchar3, uchar4, float1, float2, float3, float4.
Warning
Not efficient for MEM_GPU, use it on sparse data.
size_t getWidth ( ) const
inline

Returns the width of the matrix.

Returns
The width of the matrix in pixels.
size_t getHeight ( ) const
inline

Returns the height of the matrix.

Returns
The height of the matrix in pixels.
Resolution getResolution ( ) const
inline

Returns the height of the matrix.

Returns
The height of the matrix in pixels.
size_t getChannels ( ) const
inline

Returns the number of values stored in one pixel.

Returns
The number of values in a pixel.
MAT_TYPE getDataType ( ) const
inline

Returns the format of the matrix.

Returns
The format of the current Mat.
MEM getMemoryType ( ) const
inline

Returns the type of memory (CPU and/or GPU).

Returns
The type of allocated memory.
N* getPtr ( MEM  memory_type = MEM_CPU) const

Returns the CPU or GPU data pointer.

Parameters
memory_type: specify whether you want MEM_CPU or MEM_GPU step.
Returns
The pointer of the Mat data.
size_t getStepBytes ( MEM  memory_type = MEM_CPU) const

Returns the memory step in Bytes (the Bytes size of one pixel row).

Parameters
memory_type: specify whether you want MEM_CPU or MEM_GPU step.
Returns
The step in bytes of the specified memory.
size_t getStep ( MEM  memory_type = MEM_CPU) const
inline

Returns the memory step in number of elements (the number of values in one pixel row).

Parameters
memory_type: specify whether you want MEM_CPU or MEM_GPU step.
Returns
The step in number of elements.
size_t getStep ( MEM  memory_type = MEM_CPU) const
inline

Returns the memory step in number of elements (the number of values in one pixel row).

Parameters
memory_type: specify whether you want MEM_CPU or MEM_GPU step.
Returns
The step in number of elements.
size_t getPixelBytes ( ) const
inline

Returns the size in bytes of one pixel.

Returns
The size in bytes of a pixel.
size_t getWidthBytes ( ) const
inline

Returns the size in bytes of a row.

Returns
The size in bytes of a row.
String getInfos ( )

Return the informations about the Mat into a String.

Returns
A string containing the Mat informations.
bool isInit ( ) const
inline

Defines whether the Mat is initialized or not.

Returns
True if current Mat has been allocated (by the constructor or therefore).
bool isMemoryOwner ( ) const
inline

Returns whether the Mat is the owner of the memory it access.

If not, the memory won't be freed if the Mat is destroyed.

Returns
True if the Mat is owning its memory, else false.
ERROR_CODE clone ( const Mat src)

Duplicates Mat by copy (deep copy).

Parameters
src: the reference to the Mat to copy. This function copies the data array(s), it mark the new Mat as the memory owner.
ERROR_CODE move ( Mat dst)

Moves Mat data to another Mat.

This function gives the attribute of the current Mat to the specified one. (No copy).

Parameters
dst: the reference to the Mat to move.
Note
: the current Mat is then no more usable since its loose its attributes.
static void swap ( Mat mat1,
Mat mat2 
)
static

Swaps the content of the provided Mat (only swaps the pointers, no data copy).

This function swaps the pointers of the given Mat.

Parameters
mat1: the first mat.
mat2: the second mat.

Variables

String name
bool verbose = false
timeStamp timestamp = 0