MeeGo 1.2 Harmattan Developer Documentation Develop for the Nokia N9

FCam::Histogram Class Reference

A histogram returned by the histogram generator. More...

Collaboration diagram for FCam::Histogram:
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List of all members.

Public Member Functions

  Histogram ()
  The default constructor is an invalid histogram storing no data.
  Histogram (unsigned buckets, unsigned channels, Rect region)
  Make a new empty histogram of the given number of buckets and channels.
unsigned  operator() (int b, int c) const
  Sample the histogram at a particular bucket in a particular image channel.
unsigned &  operator() (int b, int c)
  Acquire a reference to a particular histogram entry.
unsigned  operator() (int b) const
  Sample the histogram at a particular bucket, summed over all channels.
bool  valid () const
  Is it safe to dereference data and/or call operator().
unsigned *  data ()
  Access to the raw histogram data.
unsigned  buckets () const
  How many buckets does this histogram have.
unsigned  channels () const
  How many channels does this histogram have.
Rect  region () const
  What region of the image was this histogram computed over.

Detailed Description

A histogram returned by the histogram generator.

Before you dereference the data, check if valid is true. Even if you requested a histogram, you're not guaranteed to get one back in all cases.


Constructor & Destructor Documentation

FCam::Histogram::Histogram (  )  [inline]

The default constructor is an invalid histogram storing no data.

FCam::Histogram::Histogram ( unsigned  buckets,
unsigned  channels,
Rect  region  
) [inline]

Make a new empty histogram of the given number of buckets and channels.


Member Function Documentation

unsigned FCam::Histogram::operator() ( int  b,
int  c  
) const [inline]

Sample the histogram at a particular bucket in a particular image channel.

The absolute number should not be relied on, because the histogram is computed over the bayer-mosaiced raw sensor data, which may be a different resolution to the actual output image if the imaging pipe is doing some resizing. If color histograms are available, the order of the channels is RGB, which will be in the sensor's raw color space. Despite there being twice as many green samples on the raw sensor, the green channel is normalized to have roughly the same total count as red and blue.

unsigned& FCam::Histogram::operator() ( int  b,
int  c  
) [inline]

Acquire a reference to a particular histogram entry.

Useful for creating your own histograms.

unsigned FCam::Histogram::operator() ( int  b  )  const [inline]

Sample the histogram at a particular bucket, summed over all channels.

bool FCam::Histogram::valid (  )  const [inline]

Is it safe to dereference data and/or call operator().

unsigned* FCam::Histogram::data (  )  [inline]

Access to the raw histogram data.

Stored similarly to an image: first bucket, then color channel.

unsigned FCam::Histogram::buckets (  )  const [inline]

How many buckets does this histogram have.

unsigned FCam::Histogram::channels (  )  const [inline]

How many channels does this histogram have.

Rect FCam::Histogram::region (  )  const [inline]

What region of the image was this histogram computed over.


Copyright (c) 2012, Nokia Corporation and/or its subsidiary(-ies). All rights reserved. See Copyright.
MeeGo 1.2 Harmattan API