vcmod - modify a color region image with image intensities

vcmod if= ig= [of=] [tl=] [th=] [wl=] [b=] [-a] [-d] [-m] [-c] [-v]

vcmod creates visualizations of image segmentations by modulating a set of region color labels with image intensities. The default mode is suitable for byte images where each region has a significant image intensity. Other modes are available for images with a high dynamic range (such as CT images) when the simple basic operation does not make a pleasing result (since regions for low image intensities may no longer be clearly visible.

Vcmod takes a true color image map and an original image and modifies the intensities of the color map image with the grey level values of the original image. The color map image must be byte format and have 3 channels (R,G,B), scaled from 0 to 255. The image ig= may be of any pixel type. For non-byte format, it will be windowed to a byte format, by default using the lowest and highest intensities. The output image will be a byte-formatted true color image.

By default, the program overlays transparent colors onto the image by performing a scaled multiplication operation of two input images. When the -m flag is specified, the color maps are masked over the image without transparency. Custom windowing of the original image can be specified with the values tl= and th=. Also, as an alternative, windowing may be specified by a window and level parameter wl=.

If the -d flag is specified then each region is scaled from a base value to the maximum intensity. The default base value is 0.5 of the maximum so that a marked region is always clearly visible. The base value can be set by the b= parameter. The unmarked region (color 0,0,0) is scaled over the full image intensity range (for just that region when -d is specified).

For DICOM or branded images vcmod will use the intercept and slope (ri and si) when doing windowing. When the -a flag is specified for CT images, the widowing is performed independently of each color label depending on the mean value image intensity for that label. If the mean value is less than -500 then the (lung) window is 750 with level -900; if between -500 and 175 the (tissue) window is 1000 with level 300 and if greater the 175 the (bone ) window is 1100 with level 100.

Input image if= must be a 3-channel true color image map (byte format).

if=

input true-color image map

ig=

input original image

ih=

organ color table (required for -c mode)

of=

output color-mapped image

tl=

low intensity for windowing (default: image min)

th=

high intensity for windowing (default: image max)

wl=

Alternative windowing specification by wl=<window>,<level>. Some standard window settings for CT images may also be specified by a name argument (see vdview). Permitted names are abd, lung, head, bone, byte, and nod.

b=

Base value fraction used in the -d mode. The default value is 0.5

-d

label-dependent windowing; intensities for each label are scale between the <base> fraction of the image range and the max value for that labels region.

-a

organ-dependent windowing for CT images

-m

mask over the image (default: transparent)

-c

use opacity information from color table, if any opacity value is specified then modify the color label with the image intensity, otherwise do not modify the color table value.

-v

verbose mode

vlmap

Jaesung Lee