BMENHC.DOC January 20, 1996


bmenhc.exe local contrast enhancement on bitmap file or file series.


bmenhc input.bmp [-a lower upper] [-k factor] [-m fraction] [-n kernel] [-l] [-o output[.bmp] | -p path] [-v]

Where: input.bmp is a series of bitmap files that will each be locally contrast enhanced. Wild cards (* or ?) are permitted.

-a lower upper limits of local enhancement gain.

-c limit upper and lower pixel intensity values to 0 & 255

-m fraction fraction of local mean to add back. Default is 1.0

-n kernel is kernel size in which local enhancement is perfomed. Must be odd. Default is 15.

-l list input file sewries found and performs no other action.

-k factor is gain factor. Default is 1.0

-o output[.bmp] specifies name of summed bitmap image file to be output.bmp. Default is RESULT.BMP.

-p path specifies path where output file series with same name as the input is to be placed. The path must already exist.

-v verbose displays extra information while processing images.


bmenhc performs a local contrast enhancement over a region specified by -n kernel. The gain factor for the contrast increase is given by -k factor which defaults to 1.0. The actual increase factor is limited when -a lower upper is given. Clipping is done with the -c option. With this option off it is easy to visually see over and under range clipping. With clipping enabled over and underload is handled in a more visually pleasing manner. The overall gray level may be controlled by the -m factor. Values of factor larger than 1.0 give a brighter image and vice versa. Large kernal values -n kernel give more smoothing of the contrast enhancement.


bmenhc rhodamine??.bmp : locally contrast enhances matched input files. Original image files are overwritten.

bmenhc rhodamine00.bmp rhodamine07.bmp rhodamine08.bmp : similar to above except that two difference files named result01.bmp and result.02.bmp are produced.

bmenhc rhodamine00.bmp rhodamine1?.bmp -p en : image files that match the input file specification are locally enhanced are placed in the directory en.


bmconten.exe : contrast enhance entire images.


Only works with 8 bit gray scale bitmap files. Input file extension must be explicitly specified as .BMP. In practice the option list gets rather long. It is best to have keyboard command history enabled. If the output file path does not exists an exception is generated.

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