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getPixelRegionFormatFcn

Get function handle that formats pixel value into character vector

Description

example

fun = getPixelRegionFormatFcn(imgmodel) returns a function that formats one or more pixel values in image model imgmodel as character vectors. The format of the character vectors matches the information displayed in the Pixel Region tool.

Examples

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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');

Figure contains an axes object. The axes object contains an object of type image.

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 = 1x3 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 = 1x1 cell array
    {'R:104...'}

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');

Figure contains an axes object. The axes object contains an object of type image.

im = imagemodel(h);

Specify the row and column coordinates of multiple pixels as vectors.

r = [50 400 500];
c = [250 300 500];

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

pxValue = getPixelValue(im,r,c)
pxValue = 1x3 uint8 row vector

   151    74   104

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

formatFcn = getPixelRegionFormatFcn(im);
pxRegStr = formatFcn(r,c)
pxRegStr = 3x1 cell
    {'151'}
    {'74' }
    {'104'}

Input Arguments

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Image model, specified as a scalar imagemodel object.

Output Arguments

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Pixel value format function, returned as a function handle. The function fun has two input arguments, which are the row and column coordinates of pixels in the target image. For grayscale, indexed, and binary images, fun can accept row vectors specifying multiple pixels. For RGB images, fun only accepts a single pixel. fun returns pixel values as a cell array of character vectors, formatted according to the input image type.

Image TypeSample Format of Pixel Value
Grayscale'000'
Truecolor (RGB)'R:000 G:000 B:000'
Binary'0'
Indexed'<000> R:0.00 G:0.00 B:0.00'

Data Types: function_handle

Introduced before R2006a