vop,vembed − perform an operation between two images or image sequences

vop [if=infile] [ig=<ifile2>] [of=<ofile>] [-add] [-sub] [-mul] [-div] [-mod] [-and] [-or] [-xor] [-max] [-min] [-d]

vembed [if=infile] [ig=<ifile2>] [of=<ofile>] [-add] [-sub] [-mul] [-div] [-mod] [-and] [-or] [-xor] [-max] [-min] [-d] [-ins] [-merge] [x=<val>] [y=<val>] [xy=<val>,[<val>]] [-r] [-rf]

Vop combines image pairs according to the specified operation. An image pair consists of an image from each image file. Images must match exactly with respect to size, number of channels and type.

Vembed performs a similar operation to vop except that the images to be combined do not have to be the same size. The result images are always the same size as infile1 and only the region that is the intersection of the two bounding boxes of the images is processed. Furthermore, an offset specified by command line parameters, can be added to the coordinates of the second image.

When there are multiple images in frames each image in infile1 will be matched with an image from infile2 until there are no more images in infile2, then the last image will be repeated. Similarly, if there are multiple image frames in infile1, frames will be matched in pairs until there are no more frames in infile2 then the last frame will be repeated.

There are two obvious cases: If the two files have an identical structure the correspondence between the images will be one-to-one. If imagefile2 contains just a single image it will be paired with all images in imagefile1.

All numeric image formats are accepted in general. Image pairs must be of the same type and compatible.

-add

add image2 to image1

-sub

subtract image2 from image1

-mul

multiply image1 and image2

-div

divide image1 by image2

-mod

compute image1 mod image2

-and

logical AND of image1 and image2

-or

logical OR of image1 and image2

-xor

logical exclusive OR of image1 and image2

-max

maximum value of image1 and image2

-min

minimum value of image1 and image2

-d

print some debug information

-ins

insert one image into the other (only defined for vembed)

-merge

insert one image into the other except for pixels with zero values (only defined for vembed)

x=

specify the x direction offset for the second image (only defined for vembed)

y=

specify the y direction offset for the second image (only defined for vembed)

xy=

specify both the x and y direction offsets for the second image, if only one value is given it is used for both offsets. (only defined for vembed)

-r

use relative offsets between images; i.e., consider that the origins (bottom left coordinate) of each image are mapped to the same location. This is used only for offset calculations, the bounding box for the result image is unchanged.

-rf

use relative offsets for the first image. That is the origin (bottom left coordinate) of just the first image (infile1) is mapped to (0,0) for the purpose of offset calaculations.

A. P. Reeves