Figure Properties - SERC

[...] = imread(...,'Back','none');
imread
Note If you specify a background color, you cannot output the alpha channel.
Case 3. You ask to get the alpha channel as an output variable. For example,
[A,map,alpha] = imread(filename);
[A,map,alpha] = imread(filename,fmt);
No compositing is performed; the alpha channel is stored separately from the
image (not merged into the image as in cases 1 and 2). This form of imread
returns the alpha channel if one is present, and also returns the image and any
associated colormap. If there is no alpha channel, alpha returns []. If there is
no colormap, or the image is grayscale or true color, map may be empty.
TIFF-Specific Syntax
[...] = imread(...,idx) reads in one image from a multi-image TIFF file.
idx is an integer value that specifies the order in which the image appears in
the file. For example, if idx is 3, imread reads the third image in the file. If you
omit this argument, imread reads the first image in the file.
For TIFF files, imread can read color data represented in the RGB, CIELAB or
ICCLAB color spaces. To determine which color space is used, look at the value
of the PhotometricInterpretation field returned by imfinfo. Note, however,
that if a file contains CIELAB color data, imread converts it to ICCLAB before
bringing it into the MATLAB workspace. 8- or 16-bit TIFF CIELAB-encoded
values use a mixture of signed and unsigned data types that cannot be
represented as a single MATLAB array.
[...] = imread(...,'PixelRegion',{ROWS, COLS}) returns the sub-image
specified by the boundaries in ROWS and COLS. For tiled TIFF images, imread
reads only the tiles that encompass the region specified by ROWS and COLS,
improving memory efficiency and performance. ROWS and COLS must be either
two or three element vectors. If two elements are provided, they denote the
1-based indices [START STOP]. If three elements are provided, the indices
[START INCREMENT STOP] allow image downsampling.
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