DiskGrabber¶

class DiskGrabber(*args, **kwargs)¶

Bases: FrameGrabber

Class to grab (ie. read) images from the disk.

Defined a virtual video device. “Grab” the images from the disk. Derived from the vpFrameGrabber class.

Note

See vpFrameGrabber

Here an example of capture from the directory “/local/soft/ViSP/ViSP-images/cube”. We want to acquire 10 images from the first named “image.0001.pgm” by steps of 2.

#include <visp3/core/vpImage.h>
#include <visp3/io/vpDiskGrabber.h>

int main(){
  vpImage<unsigned char> I; // Grey level image

  // Declare a framegrabber able to read a sequence of successive
  // images from the disk
  vpDiskGrabber g;

  // Set the path to the directory containing the sequence
  g.setDirectory("/local/soft/ViSP/ViSP-images/cube");
  // Set the image base name. The directory and the base name constitute
  // the constant part of the full filename
  g.setBaseName("image.");
  // Set the step between two images of the sequence
  g.setStep(2);
  // Set the number of digits to build the image number
  g.setNumberOfZero(4);
  // Set the first frame number of the sequence
  g.setImageNumber(1);
  // Set the image file extension
  g.setExtension("pgm");

  // Open the framegrabber by loading the first image of the sequence
  g.open(I) ;

  unsigned int cpt = 1;
  // this is the loop over the image sequence
  while(cpt ++ < 10)
  {
    // read the image and then increment the image counter so that the next
    // call to acquire(I) will get the next image
    g.acquire(I) ;
  }
}

Overloaded function.

__init__(self: visp._visp.io.DiskGrabber) -> None

Default constructor.

__init__(self: visp._visp.io.DiskGrabber, genericName: str) -> None

Constructor that takes a generic image sequence as input.

__init__(self: visp._visp.io.DiskGrabber, dir: str, basename: str, number: int, step: int, noz: int, ext: str) -> None

Constructor.

Parameters:

dir: Location of the image sequence.
basename: Base name of each image.
number: Initial image number.
step: Increment between two images.
noz: Number of zero to code the image number.
ext: Extension of the image file.

Methods

`__init__`	Overloaded function.
`acquire`	Overloaded function.
`close`	Not useful.
`getImageName`	Return the name of the file in which the last frame was read.
`getImageNumber`	Return the current image number.
`open`	Overloaded function.
`setBaseName`	Set the image base name.
`setDirectory`	Set the main directory name (ie location of the image sequence).
`setExtension`	Set the image extension.
`setGenericName`	Set the image generic name like image-%04d.png .
`setImageNumber`	Set the number of the image to be read.
`setNumberOfZero`	Set the step between two images.
`setStep`	Set the step between two images.

Inherited Methods

`getWidth`	Return the number of columns in the image.
`init`
`getHeight`	Return the number of rows in the image.

Operators

`__doc__`
`__init__`	Overloaded function.
`__module__`

Attributes

`__annotations__`
`init`

__init__(*args, **kwargs)¶

Overloaded function.

__init__(self: visp._visp.io.DiskGrabber) -> None

Default constructor.

__init__(self: visp._visp.io.DiskGrabber, genericName: str) -> None

Constructor that takes a generic image sequence as input.

__init__(self: visp._visp.io.DiskGrabber, dir: str, basename: str, number: int, step: int, noz: int, ext: str) -> None

Constructor.

Parameters:

dir: Location of the image sequence.
basename: Base name of each image.
number: Initial image number.
step: Increment between two images.
noz: Number of zero to code the image number.
ext: Extension of the image file.

acquire(*args, **kwargs)¶

Overloaded function.

acquire(self: visp._visp.io.DiskGrabber, I: visp._visp.core.ImageGray) -> None

Acquire an image reading the next image from the disk. After this call, the image number is incremented considering the step.

Parameters:

I: The image read from a file.

acquire(self: visp._visp.io.DiskGrabber, I: visp._visp.core.ImageRGBa) -> None

Acquire an image reading the next image from the disk. After this call, the image number is incremented considering the step.

Parameters:

I: The image read from a file.

acquire(self: visp._visp.io.DiskGrabber, I: visp._visp.core.ImageFloat) -> None

Acquire an image reading the next image from the disk. After this call, the image number is incremented considering the step.

Parameters:

I: The image read from a file.

acquire(self: visp._visp.io.DiskGrabber, I: visp._visp.core.ImageGray, image_number: int) -> None

Acquire an image reading the image with number img_number from the disk. After this call, the image number is incremented considering the step.

Parameters:

I: The image read from a file.
image_number: The number of the desired image.

acquire(self: visp._visp.io.DiskGrabber, I: visp._visp.core.ImageRGBa, image_number: int) -> None

Acquire an image reading the image with number img_number from the disk. After this call, the image number is incremented considering the step.

Parameters:

I: The image read from a file.
image_number: The number of the desired image.

acquire(self: visp._visp.io.DiskGrabber, I: visp._visp.core.ImageFloat, image_number: int) -> None

Acquire an image reading the pfm image with number img_number from the disk. After this call, the image number is incremented considering the step.

Parameters:

I: The image read from a file.
image_number: The number of the desired image.

close(self) → None¶

Not useful.

Does nothing. Here for compatibility issue with the vpFrameGrabber class.

getHeight(self) → int¶: Return the number of rows in the image.

getImageName(self) → str¶: Return the name of the file in which the last frame was read.

getImageNumber(self) → int¶: Return the current image number.

getWidth(self) → int¶: Return the number of columns in the image.

open(*args, **kwargs)¶

Overloaded function.

open(self: visp._visp.io.DiskGrabber, I: visp._visp.core.ImageGray) -> None

Read the first image of the sequence. The image number is not incremented.

open(self: visp._visp.io.DiskGrabber, I: visp._visp.core.ImageRGBa) -> None

Read the first image of the sequence. The image number is not incremented.

open(self: visp._visp.io.DiskGrabber, I: visp._visp.core.ImageFloat) -> None

Read the first image of the sequence. The image number is not incremented.

setBaseName(self, name: str) → None¶: Set the image base name.

setDirectory(self, dir: str) → None¶: Set the main directory name (ie location of the image sequence).

setExtension(self, ext: str) → None¶: Set the image extension.

setGenericName(self, genericName: str) → None¶: Set the image generic name like image-%04d.png .

setImageNumber(self, number: int) → None¶: Set the number of the image to be read.

setNumberOfZero(self, noz: int) → None¶: Set the step between two images.

setStep(self, step: int) → None¶: Set the step between two images.