getDefaultPixelInfoString

Get default pixel value as character vector

Syntax

pixval = getDefaultPixelInfoString(imgmodel)

Description

pixval = getDefaultPixelInfoString(imgmodel) returns a default pixel value character vector matching the information displayed in the Pixel Information tool, based on the type of image in imgmodel. This character vector can be used in place of actual pixel information values.

Examples

Get RGB Pixel Values from Image Model

Pixel values obtained from an imagemodel object can be returned in several formats suitable for display in different interactive image processing tools.

Create an image model associated with a color image.

h = imshow('flamingos.jpg');

im = imagemodel(h)

 
im =
 
IMAGEMODEL object accessing an image with these properties:

       ClassType: 'uint8'
    DisplayRange: []
     ImageHeight: 972
       ImageType: 'truecolor'
      ImageWidth: 1296
    MinIntensity: []
    MaxIntensity: []

 

Select a pixel by specifying row and column coordinates. This pixel has (row, column) coordinates (100, 200).

r = 100;
c = 200;

Get the numeric value of the pixel using the getPixelValue function.

pxValue = getPixelValue(im,r,c)

pxValue = 1×3 uint8 row vector

   104    95    54

Get the default pixel information string using the getDefaultPixelInfoString function. This string depends on the type of image but does not use the pixel values. The pixel information string is suitable for use with the Pixel Information tool.

defaultPxInfoStr = getDefaultPixelInfoString(im)

defaultPxInfoStr = 
'[R G B]'

Using the same string format, get the pixel information string for the specified pixel by using the getPixelInfoString function.

pxInfoStr = getPixelInfoString(im,r,c)

pxInfoStr = 
'[104 95 54]'

Get the default pixel region string using the getDefaultPixelRegionString function. This string depends on the type of image but does not use the pixel values. The pixel region string is suitable for use with the Pixel Region tool.

defaultPxRegStr = getDefaultPixelRegionString(im)

defaultPxRegStr = 
    'R:000
     G:000
     B:000'

There are two steps to get the pixel region string for the specified pixel in the same string format. First, get a function formatFcn that formats numeric pixel values by using the getPixelRegionFormatFcn function. Then, specify the row and column coordinate of the pixel as input arguments to formatFcn to get the formatted string.

formatFcn = getPixelRegionFormatFcn(im);
pxRegStr = formatFcn(r,c)

pxRegStr = 1×1 cell array
    {'R:104↵G: 95↵B: 54'}

Get Grayscale Pixel Value from Image Model

Pixel values obtained from an imagemodel object can be returned in several formats suitable for display in different interactive image processing tools.

Create an image model associated with a grayscale image.

h = imshow('liftingbody.png');

im = imagemodel(h)

 
im =
 
IMAGEMODEL object accessing an image with these properties:

       ClassType: 'uint8'
    DisplayRange: [0 255]
     ImageHeight: 512
       ImageType: 'intensity'
      ImageWidth: 512
    MinIntensity: 0
    MaxIntensity: 255

 

Select a pixel by specifying the row and column coordinates. This pixel has (row, column) coordinates (50, 250).

r = 50;
c = 250;

Get the numeric value of the pixel using the getPixelValue function.

pxValue = getPixelValue(im,r,c)

pxValue = uint8

151

Convert the numeric pixel value to a string. First, get a function formatFcn that formats numeric pixel values by using the getNumberFormatFcn. Then, specify the numeric value of the pixel as the input argument to formatFcn to get the formatted string.

formatFcn = getNumberFormatFcn(im);
pxValueStr = formatFcn(pxValue)

pxValueStr = 
'151'

Get the default pixel information string using the getDefaultPixelInfoString function. This string depends on the type of image but does not use the pixel values. The pixel information string is suitable for use with the Pixel Information tool.

defaultPxInfoStr = getDefaultPixelInfoString(im)

defaultPxInfoStr = 
'Intensity'

Using the same string format, get the pixel information string for the specified pixel by using the getPixelInfoString function.

pxInfoStr = getPixelInfoString(im,r,c)

pxInfoStr = 
'151'

Get the default pixel region string using the getDefaultPixelRegionString function. This string depends on the type of image but does not use the pixel values. The pixel region string is suitable for use with the Pixel Region tool.

defaultPxRegStr = getDefaultPixelRegionString(im)

defaultPxRegStr = 
'000'

There are two steps to get the pixel region string for the specified pixel in the same string format. First, get a function formatFcn that formats numeric pixel values by using the getPixelRegionFormatFcn function. Then, specify the row and column coordinate of the pixel as input arguments to formatFcn to get the formatted string.

formatFcn = getPixelRegionFormatFcn(im);
pxRegStr = formatFcn(r,c)

pxRegStr = 1×1 cell array
    {'151'}

Input Arguments

imgmodel — Image model

scalar imagemodel object

Image model, specified as a scalar imagemodel object.

Output Arguments

pixval — Default pixel value

'Intensity' | '[R G B]' | 'BW' | '<Index> [R G B]'

Default pixel value, returned as one of the following.

Image Type	Default Pixel Value
Grayscale	'Intensity'
Truecolor (RGB)	'[R G B]'
Binary	'BW'
Indexed	'<Index> [R G B]'

Data Types: char

Version History

Introduced before R2006a