Combine Buffers Using Formula

Combine Buffers Using Formula

This option is used to combine the intensities of two or more buffers, pixel-by-pixel, using a user-specified formula. The result is written out to a further buffer (which may be the same as one of the source buffers).

Combine 2, 3 or 4 buffers ?

Two, three or four buffers may be combined to give the resulting image. This entry specifies how many buffers will be used.

Use which buffer to give the "P" intensities ?

The pixel intensities in buffer specified here will be used as the P value in the formula (see below).

Use which buffer to give the "Q" intensities ?

The pixel intensities in buffer specified here will be used as the Q value in the formula (see below).

Use which buffer to give the "R" intensities ?

The pixel intensities in buffer specified here will be used as the R value in the formula (see below).

Use which buffer to give the "R" intensities ?

The pixel intensities in buffer specified here will be used as the R value in the formula (see below).

Use which buffer to give the "S" intensities ?

The pixel intensities in buffer specified here will be used as the S value in the formula (see below).

Combine intensities in Window or whole Screen ?

The formula applied to the intensities in the two buffers may be confined to a window (<W>) or contain the entire image (<S>).

Window Selection: Region intensities in

If the answer to the previous question specified that the intensities were to be combined from the contents of a window in the two buffers, then the window selection submenu is produced to enable the window to be specified. Information on operation of DigImage windows may be found under the [H Help] option within the submenu.

Formula combining the P and Q intensities ?

The formula to be used to combine the intensities of the two buffers should be given at this prompt. The normal DigImage expression syntax apply (consult System Overview or <shift><f1> for further details). The letter P is used to represent the intensity at a pixel in the first buffer and Q the intensity at the corresponding pixel in the second buffer.

Formula combining the P, Q and R intensities ?

The formula to be used to combine the intensities of the three buffers should be given at this prompt. The normal DigImage expression syntax apply (consult System Overview or <shift><f1> for further details). The letter P is used to represent the intensity at a pixel in the first buffer, Q the intensity at the corresponding pixel in the second buffer and R the third buffer.

Formula combining the P, Q, R and S intensities ?

The formula to be used to combine the intensities of the three buffers should be given at this prompt. The normal DigImage expression syntax apply (consult System Overview or <shift><f1> for further details). The letter P is used to represent the intensity at a pixel in the first buffer, Q the intensity at the corresponding pixel in the second buffer, R the third buffer and S the fourth buffer.

If result less than 0 or more than 255, then Saturate or Wrap ?

If the result of the above expression is negative or exceeds the maximum intensity of 255, then the result may either be saturated (<S>; to zero or 255 as appropriate), or wrapped (<W>).

Place resulting image where ?

The image resulting from combining the intensities will be placed in the buffer specified at this prompt. Any DigImage buffer may be used (including one of the source buffers). The selected buffer is made the current output buffer. The buffer is NOT cleared prior to the calculation, meaning that if a window is used, regions outside the window will be preserved.

Message:
Combining intensities...


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Stuart Dalziel, last page update: 19 February 1996