Learn more about Video and Image Processing Blockset

Image From File - Import image from image file

Library

Sources

Description

Use the Image From File block to import an image from a supported image file. For a list of supported file formats, see the imread function reference page in the MATLAB documentation. If the image is a M-by-N array, the block outputs a binary or intensity image, where M and N are the number of rows and columns in the image. If the image is a M-by-N-by-P array, the block outputs a color image, where M and N are the number of rows and columns in each color plane, P.

Port	Output	Supported Data Types	Complex Values Supported
Image	M-by-N matrix of intensity values or an M-by-N-by-P color video signal where P is the number of color planes	Double-precision floating point Single-precision floating point Fixed point Boolean 8-, 16-, 32-bit signed integer 8-, 16-, 32-bit unsigned integer	Yes
R, G, B	Scalar, vector, or matrix that represents one plane of the input RGB video stream. Outputs from the R, G, or B ports have the same dimensions.	Same as I port	Yes

For the Video and Image Processing Blockset blocks to display video data properly, double- and single-precision floating-point pixel values must be between 0 and 1. If the input pixel values have a different data type than the one you select using the Output data type parameter, the block scales the pixel values, adds an offset to the pixel values so that they are within the dynamic range of their new data type, or both.

Use the File name parameter to specify the name of the graphics file that contains the image to import into the Simulink modeling and simulation software. If the file is not on the MATLAB path, use the Browse button to locate the file. This parameter supports URL paths.

Use the Sample time parameter to set the sample period of the output signal.

Use the Image signal parameter to specify how the block outputs a color video signal. If you select One multidimensional signal, the block outputs an M-by-N-by-P color video signal, where P is the number of color planes, at one port. If you select Separate color signals, additional ports appear on the block. Each port outputs one M-by-N plane of an RGB video stream.

Use the Output port labels parameter to label your output ports. Use the spacer character, |, as the delimiter. This parameter is visible if you set the Image signal parameter to Separate color signals.

On the Data Types pane, use the Output data type parameter to specify the data type of your output signal.

Dialog Box

The Main pane of the Image From File dialog box appears as shown in the following figure.

File name

Specify the name of the graphics file that contains the image to import into the Simulink environment.

Sample time

Enter the sample period of the output signal.

Image signal

Specify how the block outputs a color video signal. If you select One multidimensional signal, the block outputs an M-by-N-by-P color video signal, where P is the number of color planes, at one port. If you select Separate color signals, additional ports appear on the block. Each port outputs one M-by-N plane of an RGB video stream.

Output port labels

Enter the labels for your output ports using the spacer character, |, as the delimiter. This parameter is visible if you set the Image signal parameter to Separate color signals.

The Data Types pane of the Image From File dialog box appears as shown in the following figure.

Output data type

Specify the data type of your output signal.

Signed

Select to output a signed fixed-point signal. Otherwise, the signal will be unsigned. This parameter is only visible if, from the Output data type list, you select Fixed-point.

Word length

Specify the word length, in bits, of the fixed-point output data type. This parameter is only visible if, from the Output data type list, you select Fixed-point.

Set fraction length in output to

Specify the scaling of the fixed-point output by either of the following two methods:

• Choose Best precision to have the output scaling automatically set such that the output signal has the best possible precision.

• Choose User-defined to specify the output scaling in the Fraction length parameter.

This parameter is only visible if, from the Output data type list, you select Fixed-point or when you select User-defined.

Fraction length

For fixed-point output data types, specify the number of fractional bits, or bits to the right of the binary point. This parameter is only visible when you select Fixed-point or User-defined for the Output data type parameter and User-defined for the Set fraction length in output to parameter.

User-defined data type

Specify any built-in or fixed-point data type. You can specify fixed-point data types using the sfix, ufix, sint, uint, sfrac, and ufrac functions from the Simulink Fixed Point library. This parameter is only visible when you select User-defined for the Output data type parameter.

See Also

From Multimedia File	Video and Image Processing Blockset software
Image From Workspace	Video and Image Processing Blockset software
To Video Display	Video and Image Processing Blockset software
Video From Workspace	Video and Image Processing Blockset software
Video Viewer	Video and Image Processing Blockset software
im2double	Image Processing Toolbox software
im2uint8	Image Processing Toolbox software
imread	MATLAB

Image Data Type Conversion

Image From Workspace

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