readEncodedStrip

Read data from specified strip

Syntax

stripData = readEncodedStrip(t,stripNumber)

[Y,Cb,Cr] = readEncodedStrip(t,stripNumber)

Description

stripData = readEncodedStrip(t,stripNumber) returns the image data from the strip specified by stripNumber from the TIFF file represented by the Tiff object t.

The readEncodedStrip function trims the area in a strip that falls outside of the ImageLength boundary. Therefore, image data from a strip at the bottom edge of the image can have different dimensions.

[Y,Cb,Cr] = readEncodedStrip(t,stripNumber) returns the YCbCr components of the strip data specified by stripNumber from the TIFF file represented by the Tiff object t. Use this syntax only with images that have a YCbCr photometric interpretation.

Depending upon the values of the YCbCrSubSampling tag, the size of the Cb component can differ from the Y component.

Examples

Read Strip of Data from TIFF Image

Read a strip of image data from a TIFF file that contains an image with a stripped layout.

t = Tiff('peppers_RGB_stripped.tif','r');

Determine the number of strips and the length of the strip in the image.

numberOfStrips(t)

ans = 
6

getTag(t,'RowsPerStrip')

ans = 
35

Read and display the third strip of the image. The readEncodedStrip function trims the area in a strip that falls outside of the ImageLength boundary. Therefore, image data from a strip at the bottom edge of the image can have different dimensions.

strip = readEncodedStrip(t,3);
imshow(strip);
title('3^{rd} Strip Peppers Image');

Close the Tiff object.

close(t);

Read Strip of Data from YCbCr TIFF Image

Read a strip of image data from a YCbCr TIFF file that contains an image with a stripped layout.

t = Tiff('peppers_YCbCr_stripped.tif','r');

Determine the number of strips and the length of each strip in the image.

numberOfStrips(t)

ans = 
6

getTag(t,'RowsPerStrip')

ans = 
35

Read and display the Y component of the third strip of the image. The readEncodedStrip function trims the area in a strip that falls outside of the ImageLength boundary. Therefore, image data from a strip at the bottom edge of the image can have different dimensions.

[Y,Cb,Cr] = readEncodedStrip(t,3);
imshow(Y);
title('3^{rd} Strip of Peppers Image (YCbCr)')

Close the Tiff object.

close(t);

Input Arguments

t — Tiff object

Tiff object

Tiff object representing a TIFF file. Use the Tiff function to create the object.

stripNumber — Strip number

positive integer

Strip number, specified as a positive integer. Strip numbers are one-based numbers.

Example: 15

Data Types: double

Output Arguments

stripData — Strip data

numeric array

Strip data, returned as a numeric array.

Y — Luma component

numeric array

Luma component of the strip data, returned as a two-dimensional numeric array.

Cb — Blue-difference chroma component

numeric array

Blue-difference chroma component of the strip data, returned as a two-dimensional numeric array.

Cr — Red-difference chroma component

numeric array

Red-difference chroma component of the strip data, returned as a two-dimensional numeric array.

Limitations

• readEncodedStrip returns image data from SVS files as RGB data only, even for SVS files with YCbCr photometric interpretation.

Algorithms

References

This function corresponds to the TIFFReadEncodedStrip function in the LibTIFF C API. To use this method, you must be familiar with the TIFF specification and technical notes. View this documentation at LibTIFF - TIFF Library and Utilities.

Version History

Introduced in R2009b