Simple question, how to read in a color band file?

FREAD Read binary data from file. A = FREAD(FID) reads binary data from the specified file and writes it into matrix A. FID is an integer file identifier obtained from FOPEN. MATLAB reads the entire file and positions the file pointer at the end of the file (see FEOF for details). A = FREAD(FID,SIZE) reads the number of elements specified by SIZE. Valid entries for SIZE are: N read N elements into a column vector. inf read to the end of the file. [M,N] read elements to fill an M-by-N matrix, in column order. N can be inf, but M can't. A = FREAD(FID,SIZE,PRECISION) reads the file according to the data format specified by PRECISION. The PRECISION input commonly contains a datatype specifier like 'int' or 'float', followed by an integer giving the size in bits. The SIZE argument is optional when using this syntax. Any of the following values, either the MATLAB version, or their C or Fortran equivalent, may be used for PRECISION. If not specified, the default PRECISION is 'uint8'. MATLAB C or Fortran Description 'uchar' 'unsigned char' unsigned integer, 8 bits. 'schar' 'signed char' signed integer, 8 bits. 'int8' 'integer*1' integer, 8 bits. 'int16' 'integer*2' integer, 16 bits. 'int32' 'integer*4' integer, 32 bits. 'int64' 'integer*8' integer, 64 bits. 'uint8' 'integer*1' unsigned integer, 8 bits. 'uint16' 'integer*2' unsigned integer, 16 bits. 'uint32' 'integer*4' unsigned integer, 32 bits. 'uint64' 'integer*8' unsigned integer, 64 bits. 'single' 'real*4' floating point, 32 bits. 'float32' 'real*4' floating point, 32 bits. 'double' 'real*8' floating point, 64 bits. 'float64' 'real*8' floating point, 64 bits. The following platform dependent formats are also supported but they are not guaranteed to be the same size on all platforms. MATLAB C or Fortran Description 'char' 'char*1' character. 'short' 'short' integer, 16 bits. 'int' 'int' integer, 32 bits. 'long' 'long' integer, 32 or 64 bits. 'ushort' 'unsigned short' unsigned integer, 16 bits. 'uint' 'unsigned int' unsigned integer, 32 bits. 'ulong' 'unsigned long' unsigned integer, 32 bits or 64 bits. 'float' 'float' floating point, 32 bits. If the precision is 'char' or 'char*1', MATLAB reads characters using the encoding scheme associated with the file. See FOPEN for more information. The following formats map to an input stream of bits rather than bytes. 'bitN' signed integer, N bits (1<=N<=64). 'ubitN' unsigned integer, N bits (1<=N<=64). If the input stream is bytes and FREAD reaches the end of file (see FEOF) in the middle of reading the number of bytes required for an element, the partial result is ignored. However, if the input stream is bits, then the partial result is returned as the last value. If an error occurs before reaching the end of file, only full elements read up to that point are used. By default, numeric and character values are returned in class 'double' arrays. To return these values stored in classes other than double, create your PRECISION argument by first specifying your source format, then following it by '=>', and finally specifying your destination format. If the source and destination formats are the same then the following shorthand notation may be used: *source which means: source=>source For example, uint8=>uint8 read in unsigned 8-bit integers and save them in an unsigned 8-bit integer array *uint8 shorthand version of previous example bit4=>int8 read in signed 4-bit integers packed in bytes and save them in a signed 8-bit integer array (each 4-bit integer becomes one 8-bit integer) double=>real*4 read in doubles, convert and save as a 32-bit floating point array A = FREAD(FID,SIZE,PRECISION,SKIP) includes a SKIP argument that specifies the number of bytes to skip after each PRECISION value is read. If PRECISION specifies a bit source format, like 'bitN' or 'ubitN', the SKIP argument is interpreted as the number of bits to skip. The SIZE argument is optional when using this syntax. When SKIP is used, the PRECISION specifier may contain a positive integer repetition factor of the form 'N*' which prepends the source format of the PRECISION argument, like '40*uchar'. Note that 40*uchar for the PRECISION alone is equivalent to '40*uchar=>double', not '40*uchar=>uchar'. With SKIP specified, FREAD reads in, at most, a repetition factor number of values (default of 1), does a skip of input specified by the SKIP argument, reads in another block of values and does a skip of input, etc. until SIZE number of values have been read. If a SKIP argument is not specified, the repetition factor is ignored. Repetition with skip is useful for extracting data in noncontiguous fields from fixed length records. For example, s = fread(fid,120,'40*uchar=>uchar',8); reads in 120 characters in blocks of 40 each separated by 8 characters. A = FREAD(FID,SIZE,PRECISION,SKIP,MACHINEFORMAT) treats the data read as having a format given by the MACHINEFORMAT. You can obtain the MACHINEFORMAT argument from the output of the FOPEN function. See FOPEN for possible values for MACHINEFORMAT. The SIZE and SKIP arguments are optional when using this syntax. [A, COUNT] = FREAD(...) Optional output argument COUNT returns the number of elements successfully read. Examples: The file alphabet.txt contains the 26 letters of the English alphabet, all capitalized. Open the file for read access with fopen, and read the first five elements into output c. Because a precision has not been specified, MATLAB uses the default precision of uchar, and the output is numeric: fid = fopen('alphabet.txt', 'r'); c = fread(fid, 5)' c = 65 66 67 68 69 fclose(fid); This time, specify that you want each element read as an unsigned 8-bit integer and output as a character. (Using a precision of 'char=>char' or '*char' will produce the same result): fid = fopen('alphabet.txt', 'r'); c = fread(fid, 5, 'uint8=>char')' c = ABCDE fclose(fid); See also FWRITE, FSEEK, FSCANF, FGETL, FGETS, LOAD, FOPEN, FEOF. Documentation for fread doc fread Other uses of fread i2c/fread instrument/fread serial/fread udp/fread icinterface/fread