PLEASE NOTE : This is the documentation for the avs module executable subregion, which contains the following modules: vextcent vextract vinsert vpad vsamp Any mention of xvimage is actually a "field 2D". Also, the INPUTs and OUTPUTs, which are mapped to avs parameters, inputs, and outputs, are for the khoros library routine. ********************************************************************************* Documentation for avs module vextcent INPUT OUTPUT DESCRIPTION Extracts the center of an image and places the result in the specified output image. The dimensions of the extracted area are specified by the height (-h) and width (-w) arguments. The dimensions of the resulting output image correspond to the extracted area. If subimage is larger than the original image, the routine will fail. SEE ALSO intro(1), verror(3), vgparms(3), vutils(3) RESTRICTIONS Will not operate on BIT, and transform data storage types. COPYRIGHT Copyright 1991, University of New Mexico. All rights reserved. ********************************************************************************* Documentation for avs module vextract INPUT img1 the input xvimage structure xoff the x offset from the upper left hand corner of the input image. yoff the y offset from the upper left hand corner of the input image. width the row_size of the output image height the col_size of the output image copymapflag copy map only if set OUTPUT *img2 holds the result of the extract operation. DESCRIPTION vextract removes a rectangular piece from an image to pro- duce a subimage. The output image has the same characteris- tics as the input image except for a subset of the data and the subimage parameters are set. The location data will always be preserved from the original image. The map data may or may not be copied to the new subimage. struct xvimage *img1 img1 is used as the input xvimage structure. struct xvimage **img2 img2 will be the resulting image. img1 is not touched. Memory for img2 will be allocated. int xoff xoff specifies the X offset in the input image for the upper left corner of the subimage. int yoff yoff specifies the Y offset in the input image for the upper left corner of the subimage. int width width specifies the row_size of the resulting subimage. int height height specifies col_size of the resulting subimage. int copymapflag copymapflag if set to TRUE will copy the map data. If set to FALSE will not copy the map data. The subimage parameters are set to reflect where the subim- age was taken from the origonal image. If the subimage specification extends beyond the image boun- dary, the largest possible subimage is returned. If the subimage is larger than the original image, the routine will fail. vextract returns a zero upon failure and a one upon suc- cess. SEE ALSO vextract(1), intro(3), vipl(3), verror(3), vutils(3) AUTHOR John Rasure, Mark Young COPYRIGHT Copyright 1991, University of New Mexico. All rights reserved. ********************************************************************************* Documentation for avs module vinsert INPUT img1 input xvimage structure img2 input xvimage structure for subimage xoff specifies the upper left X coordinate for the placement of the subimage. yoff specifies the upper left Y coordinate for the placement of the subimage. real specifies the real value for padding imag specifies the imaginary value for padding with COMPLEX OUTPUT img1 holds the result of the insert operation. The output data type is the same as the input data type. DESCRIPTION vinsert inserts a subimage into the input image to form the output image. The subimage is placed at the same coordi- nates is was extracted from unless the xoffset and yoffset of the upper left corner of the target location are speci- fied. If the subimage does not completely fit into the input image, then the input image will be padded to a larger size to encompass the subimage. The real variable specifies the padding value for the larger size image. In the event that images are of data storage type COMPLEX, the imag variable specifies the imaginary pad value. For byte type images: If the level value specified by user is greater than 255, the level value will be scaled down to 255. If the level specified by user is less than 0, the level value will by scaled up to 0. There are no restrictions to the input image (img1) and the subimage (img2) size. It is possible to input a large image into a small image, thus the small image will no longer exist. This routine will work on multiple band images. But both input images must contain the same number of data bands. The input image and subimage must be of the same data storage type. The output image is the same data storage type as the input image. img1 is used for both the input xvimage structure and the output result xvimage structure. This is done to save space, but you must be careful not to overwrite impor- tant data. img2 should contain a smaller subimage. xoff and yoff specify the location at which the subimage should be placed. real specifies the padding value for real data, and in the case of COMPLEX data imag specifies the padding value for the imaginary part. vinsert returns a zero upon failure and a one upon success. SEE ALSO vinsert(1), intro(3), vipl(3), verror(3), vutils(3) AUTHOR John Rasure, Tom Sauer, Mark Young COPYRIGHT Copyright 1991, University of New Mexico. All rights reserved. ********************************************************************************* Documentation for avs module vpad INPUT OUTPUT DESCRIPTION Performs the padding of a data sequence. Specifying an offset other than zero generates a border around the original image. If the input image type is not complex, the imaginary pad value will be ignored. For byte images, pad values greater than 255 will be reduced to 255. SEE ALSO intro(1), verror(3), vgparms(3), vutils(3) RESTRICTIONS Will not operate on transformed or BIT type images COPYRIGHT Copyright 1991, University of New Mexico. All rights reserved. ********************************************************************************* Documentation for avs module vsamp INPUT image pointer to image to be sampled line pointer to image pointer to receive the out- put image x1 X coordinate of start point y1 Y coordinate of start point x2 X coordinate of end point y2 Y coordinate of end point n number of samples to generate between the endpoints OUTPUT line xvimage pointer indicated by line is attached to the new image DESCRIPTION Given an image of arbitrary size and a line through that image, sample the image along the line. The sampling inter- val is independent of image size and line orientation. The value at each sample point is obtained by bilinear interpo- lation. The first sample point is precisely at the starting point and the final sample is precisely at the ending point. SEE ALSO vsamp(1), intro(3), vipl(3), verror(3), vutils(3) RESTRICTIONS vsamp will only work on images of type FLOAT. AUTHOR Richard Krukar COPYRIGHT Copyright 1991, University of New Mexico. All rights reserved. *********************************************************************************