The Datafile PD-CD 5/DATAFILE_PDCD5.iso/education/a/easyknit/KnitConv/Manual/ConvManual

Text File | 1997-01-23 | 32.5 KB | 677 lines

                    ***KnitConv Introduction***

   A companion program for !EasyKnit, !KnitConv is a file conversion
   utility which manipulates EasyKnit files in a variety of ways.
   KnitConv requires RISC OS 3.1 or above in order to operate.

   It allows you to :
   1. Create a Grid only EasyKnit file from a Grid and Picture
      file, reducing the file size for storage. Useful after the stitch
      grid has been appropriately filled and the Picture is not needed.

   2. Capture the EasyKnit Edit window as a Sprite file in low or
      high resolution and with 16 or 256 colours. (see Creating
      sprites p. 9)

   3. Convert pattern blocks designed on an EasyKnit grid into
      Double Jacquard patterns utilising the standard, elongated,
      or jigsaw method of translation.
      Experienced computer users should find the prompts supplied by the
      program to be enough to get started. If you need a bit more help,
      EasyKnit can provide it through the computer’s interactive help
      system. A click on the  help button in the program’s KnitConv
      window will start it up for you. (see Diagram 1 ).


             ***Using !KnitConv***

   The basic steps in the use of KnitConv are:

     1. Prepare a suitable EasyKnit file using the !EasyKnit
     program. eg. a pattern block designed on a blank grid for
     conversion to a Double Jacquard pattern.
     2. Load the KnitConv program onto the icon bar by double
     clicking on its icon in a filer window, then open KnitConv’s
     KnitConv window by clicking on it’s icon bar icon.
     3. Open the menu by clicking on the pop-up menu button in
     the KnitConv window (diagram 1 p. 3) and choose the
     conversion process you wish to perform from the list of
     those available.
     4. Drag the EasyKnit file you want to convert from the filer
     window onto the KnitConv icon bar icon or into the
     program’s KnitConv window.
     5. Provide a suitable name for the processed file then drag the
     file icon from the Save area (diagram 1 p. 3) of the
     KnitConv program’s KnitConv window to a directory
     viewer.

   This will initiate the conversion process and, after a short delay while
   processing is carried out, the new file will be created in the filer
   window.
   The program will then be reset and will wait for another processing
   option to be chosen.


                 ***The KnitConv window***

   Double click on KnitConv’s icon in a filer window to load it onto the
   icon bar and then click on its icon bar icon to open !KnitConv’s
   KnitConv window. (see diagram 1).
   The Save area, which is initially greyed out will be ungreyed when it
   becomes appropriate.

                   <insert Diagram 1.>

   1. Click on the help button to start the computer’s interactive
      help system. This will provide information about whatever is
      under the pointer as it is moved around within the program’s
      windows and menu structure.
   2. This panel displays information about the currently chosen
      process or, initially, asks you to choose the process you
      wish to perform.
   3. Click on this pop-up menu button to open a list of available
      processes to choose from.
   4. This is the Prompt panel, It serves as a reminder of what
      you should do next as you operate the KnitConv program.
   5. This is the Save area. It remains greyed out until a process
      has been chosen and the file to convert has been dragged in.
      It then shows a suitable file icon for the kind of file to be
      created and allows you to provide it with a relevant name.
      Once named, dragging the file icon to a filer window will
      initiate the processing and after a short delay the newly
      created file will appear in the filer window.

               ***The Colour Picker window***

   The Colour picker window appears automatically if the program
   needs to have nominated one of the colours available in the file to be
   processed. eg. When producing a jig-saw type of double jacquard
   pattern the program needs to know which colour should be treated
   as the background yarn colour in order to produce the correct result
   for the output file. (see diagram 2).

                     <insert diagram 2.>

   The Colour Picker window is similar in operation to the colour
   picker window in EasyKnit. The panel at the top describes the
   decision the program is asking to have made for it.
   Click on the colour panel, or its colour name to select the relevant
   choice then confirm it by clicking on the Continue button. The
   program will then be able to proceed as required.
   If you click on the Cancel button, the Colour Picker window will
   close and the program will revert to waiting for a process to be
   chosen.

   The program will not open the colour picker window if it finds that
   one of the colour panels has one of the following (case sensitive)
   names:
         bkgnd           Bkgnd
         background      BkGnd
         Background      BackGround
         main            Main

   It will use the named colour, if one is found, as the background
   colour. Otherwise the Colour picker window will open and you will
   be asked to confirm the colour to be used.


                ***Menus and Dialogue Boxes***

   This section of the manual provides a description of the various
   menus and dialogue boxes used by the program. Menu items with a
   rightward pointing arrow lead to sub-menus which have a range of
   options associated with the menu entry. Moving the pointer off to
   the right of an arrow will open that option’s sub-menu allowing more
   detailed choices to be made.

   *Icon bar menu*

   This menu is associated with the program’s icon bar icon.

   The Icon bar/Info option leads to a standard
   information box giving details about the KnitConv
   program.

   Icon bar/Quit is the standard method of discarding
   the program from memory when no longer required.


   *Processes menu*

   The Processes menu is associated with the pop-up menu button in
   KnitConv’s main window. It can be opened by clicking with the Select or
   Menu mouse buttons while the pointer is over the pop-up button.

      Processes/Remove picture
   Choose this process to remove the Picture file from a Grid and
   picture EasyKnit file after the stitch grid has been filled and the
   Picture file is no longer required. This reduces the size of the file for
   storage purposes but is an irreversible step. The Picture cannot be
   recombined with the filled grid. Once the grid has been filled the
   picture becomes redundant and if you are unlikely to want to edit the
   grid with the help of the Picture file in the future, then it can safely
   be removed. The file produced as a result of this process is a Grid
   Only type EasyKnit file which can be used as normal by EasyKnit.

      Processes/Make sprite
   Choose this option to create the EasyKnit file’s Edit window as a
   Low resolution, 16 colour sprite file, or preferably, move the pointer
   off to the right over the arrow to open the Sprite sub-menu allowing
   more control over the output sprite. (see Creating sprites below).

      Processes/Double Jacquard
   Choose this option to create a standard Double Jacquard pattern.
   Moving off to the right over the arrow opens the Jacquard sub-menu
   allowing the other available Jacquard processing options to be
   chosen. (see Jacquard processes below for more info.)

      Processes/Make sprite/Sprite menu
   For more information about making the best use of the options in
   this menu see the section Creating sprites below.

      Sprite/Low res
   Choose the Low res option to create a rectangular pixel mode sprite.
   This uses less memory than a square pixel mode sprite but can lead to a
   loss of detail in the image produced and consequent lack of crispness.

      Sprite/High res
   Choose the High res option to create a square pixel mode sprite.
   This requires more free memory than a Low res sprite but is better at
   preserving image detail.

      Sprite/16 Colours
   Choose the 16 Colours option if the all the colours in the file to be
   processed were created using the 16 colour area of EasyKnit’s
   Colour picker window. If a picture file is included in the input file
   then it will only reproduce correctly if all its colours are also defined
   using the 16 colour palette.
   If the Picture or EasyKnit file contain colours defined using the 256
   colour palette then use the 256 Colours option to ensure accurate
   colour reproduction.
   The 16 Colour option creates a sprite which requires less memory
   than a 256 colour sprite and is preferable unless  some colours to be
   used are defined using the 256 colour palette.

      Sprite/256 Colours
   Choose the 256 Colours option if the incoming EasyKnit file or a
   Picture file held within it contain colours defined using the 256 colour
   palette to ensure accurate colour reproduction.
   This option creates a sprite which requires more memory than a 16
   colour sprite and is necessary if any colours in the input file are
   defined using the 256 colour palette.

      Sprite/Include picture
   Chose the Include picture option if you wish to have the Picture file
   contained within the input file included in the image generated. The
   Picture file will appear behind the grid of stitches and will show
   through any unfilled stitches but will be covered by filled grid
   stitches.
   If this option is left unticked, any Picture file present in the input file
   will be ignored.

      Sprite/Scale
   Move off to the right from the Sprite/Scale option to open the
   Scale dialogue box.

   Set the values in the two icons to the correct ratio to alter the size of
   the produced sprite. eg. 1:1 gives a sprite which is the same size as
   the original Edit window, 2:1 gives a sprite which is twice the size of
   the original, 3:4 gives a sprite which is three quarters the size of the
   original etc.

   Processes/Double Jacquard/Jacard menu

      Jacquard/Standard
   The Standard option produces a normal Double Jacquard pattern. For each
   row of input, each colour-row of the output pattern appears twice.

      Jacquard/Elongated
   The Elongate option produces an Elongated Jacquard pattern. For
   each row of input, each colour-row of the output pattern appears
   once and the machine uses its elongate button to advance the
   punchcard on alternate rows.

      Jacquard/Jigsaw
   The Jigsaw option produces a Jigsaw Jacquard pattern. The input
   rows are examined in sequential pairs to determine the colour order
   of the output rows of the pattern.


                     ***Creating sprites***

   KnitConv has various options available when creating sprites, the
   options are there to assist users to produce the best quality result
   within the memory limitations of their computer and the capability
   of their printer.

   Hopefully the following discussion will shed some light on the
   numerous things which need to be taken into account when using
   KnitConv to produce the EasyKnit Edit window as a sprite file and
   assist you in creating the best possible results.

   *About sprites*

   A sprite is a method of storing and manipulating graphical images in
   a computer. A sprite is in fact a very similar arrangement to a filled
   EasyKnit grid. It consists of a regular block of pixels layed out in an
   array of rows and columns, each pixel is similar to the individual
   stitches making up an EasyKnit grid, though a pixel’s size is fixed and
   its shape can be square or rectangular depending on its screen mode.
   Each pixel can be individually set to be shown in one of a range of
   colours available for a sprite created in that screen mode. eg. In a 16
   colour sprite, each pixel can be any one of the 16 possible colours
   available in the 16 colour palette. Similarly pixels in 256 colour sprites
   can display any of the colours available in the 256 colour palette.
   Sprites can also be created in screen modes with 2, 4, 32 thousand
   and 16 million colours available to them. We are primarily concerned
   with 16 or 256 colour sprites as these have the same colours available
   to them as are available for use within EasyKnit.

   Users of computers with small amounts of RAM in their machines
   may well be limited regarding the Scale setting and, therefore, the
   size of sprite for which KnitConv can find enough free memory to
   create a sprite of a large grid. If the program tells you that there is
   not enough free memory available to create the desired sprite then
   you should try to maximise the amount of free RAM available for
   use by quitting any unnecessary applications from the icon bar and/
   or creating the sprite at a reduced Scale setting so that its creation
   requires less memory.

   Some very large grids may not be possible to create at all on low
   memory machines due to the fact that if the scale setting for creating
   the sprite is reduced to a low point where the sprite produced will fit
   within the available memory then you may find that some of the
   detail, particularly fine details like the gridlines, can end up being
   missed out during creation of the sprite, thus rendering the image
   useless. The only solution to this problem is to add extra RAM
   capacity by purchasing a memory upgrade for your computer.
   Sprite files can be viewed and edited by the Paint program supplied
   with the computer. Double click on a sprite file icon in a filer window
   to load it into Paint.

   When Paint loads a sprite file it opens a Sprite file window
   containing a miniature version of the sprite image. Double click on
   the miniature image to open a sprite window containing the full
   version of the sprite which can be edited as required.
   Press Menu when the pointer is over the sprite file window and
   choose the Display/Full info option, then if necessary, click on the
   sprite file window’s toggle size icon (top right), to allow you to find
   out more information about the type of sprite contained in the sprite
   file, such as its screen mode, (which defines whether it is a 16 or a 256
   colour sprite and the shape of its pixels) and its width and height in
   pixels and the number of bytes of memory needed for the sprite.
   (divide the number of bytes required to hold the sprite by 1024 for an
   accurate measure of its size in kilobytes, or divide by 1000 for a rough
   estimate).


              ***Choosing the number of Colours***

   It is possible in KnitConv to create a sprite as:

      a low resolution sprite of 16 colours, (mode 12)
      a low resolution sprite of 256 colours, (mode 15)
      a high resolution sprite of 16 colours, (mode 20)
      a high resolution sprite of 256 colours, (mode 21)

   Modes 12 and 15 are created from rectangular pixels while modes 20
   and 21 use square shaped pixels. The square pixel modes are capable
   of resolving finer details and produce crisper looking sprites than the
   rectangular pixel modes but it does require more RAM to create and
   thereafter to utilise them in other programs.

   A 256 colour sprite of a given size in pixels requires twice as much
   memory as a 16 colour sprite of the same size if both sprites are
   created in a screen mode which has square shaped pixels or in a
   screen mode with rectangular shaped pixels.

   When displayed on the screen, a sprite created in a rectangular pixel
   mode will require half the amount of memory needed for a square
   pixel mode sprite of the same physical size on the screen.

   The 16 colours available for use in a 16 colour sprite are also present
   scattered among the wider range of colours available in a 256 colour
   sprite. This means that a sprite created in KnitConv as a 256 colour
   sprite but which uses only those colours available to a 16 colour
   sprite will look identical to a sprite created by KnitConv as a 16
   colour sprite but the 256 colour version will need twice as much free
   memory to create and manipulate.

   This is obviously wasteful of precious memory for no real gain so if
   all the colours used in the EasyKnit file you wish to capture as a
   sprite have been chosen from the 16 colour part of the Colour picker
   window then you should use the 16 Colour option in KnitConv’s
   Sprite menu when creating the sprite.

   When the computer is asked to represent one of the colours defined
   from the 256 colours part of the colour picker window, in a sprite
   with only 16 colours available, the computer decides which of the 16
   colours available is closest to the colour in question and uses its
   choice to represent that colour. Since 8 of the 16 colours available
   are black, white or intermediate shades of grey, this process rarely
   produces a usable result. The colours in the original file are badly
   corrupted in the output sprite rendering it unusable for most
   purposes.

   If any of the colours defined in the input EasyKnit file have been
   chosen from the 256 colours part of the colour picker window then it
   is necessary to select the 256 Colours option in KnitConv’s Sprite
   menu to ensure correct representation in the output sprite of the
   colours used in the input file.

   Similarly, if the input file contains a Picture file and the picture file
   or parts of it are visible in the Edit window to be captured as a sprite
   and the picture file uses colours defined from a 256 colour palette,
   then you will need to use the 256 Colours menu option to get the
   colours to reproduce correctly. (tick the Include picture menu option
   if you wish to have the Picture file included).

   If the EasyKnit file colours have been defined from the 16 colour
   part of the Colour picker window but the picture file is a 256 colour
   file it is still possible to produce a 16 colour sprite from it but only if
   the picture file is not to be included in the output.


                      ***Viewing 256 colour sprites***

   Your computer may well be configured to start up in a 16 colour
   screen mode when first switched on. If this is the case then if you
   want to view the result of creating a 256 colour sprite on screen then
   you must remember to switch into a 256 colour screen mode first
   otherwise the colours in the sprite, although correct, will look on the
   screen as if they are wrong. Changing to a 256 colour screen mode
   will rectify this apparent problem.

   *Setting the scale factor*

   The setting in the Scale dialogue box allows you to alter the overall
   width and height of the sprite created. A setting of 1:1 creates a
   sprite which is the same size as the Edit window, (this may well be
   larger than the screen size). Setting the scaling ratio to 1:3 reduces the
   size of the sprite created to be one third as large as the Edit window.
   Setting the ratio to 4:1 creates a sprite which is 4 times larger than
   the input Edit window.

   If you prefer to work with percentages rather than fractions in the
   Scale box, simply set the figure in the second writable icon to be
   100. The figure in the first icon can then be set to the percentage
   figure required. eg 66:100 is the same as  a setting of 66%.
   The scaling procedure used by KnitConv utilises the computer’s built
   in sprite scaling routines. These are not very sophisticated and while
   creating a sprite at 1:1 or increasing the sprite’s size to greater than
   that of the Edit window poses no problems, there is a limit to how
   much you can reduce the size of the sprite using a scale setting
   which is less than 1:1 before you start to loose significant detail. The
   gridlines being narrow are particularly prone to disappearing from
   the created sprite if the scale of the output is reduced by too much.
    This can happen because of the way in which the computer creates
   the scaled sprite. When you create a sprite at a scale setting of 1:1,
   each row of pixels which make up the Edit window as it appears on
   the screen is recreated as a row of pixels in the sprite file. Thus an
   exact copy of the Edit window is created as a sprite file. However,
   when you reduce the scale setting from 1:1 to say 1:3 then the
   computer simply ignores 2 rows of pixels out of three in the Edit
   window writing every third row to the output sprite. No account of
   the information stored in the ignored rows is taken, so if two of the
   rows which are being ignored happen to be used to represent one of
   the gridlines then that gridline will not appear in the sprite created.
   The precise setting of the Scale factor at which this will happen
   depends on the overall size of the grid and the size of the stitches
   which make it up. Trial and error is the only way to find out if a given
   scale setting is capable of producing an acceptable result.


                    ****Coping with large sprites****

   It may be that you find that the smallest scale setting by which you
   can reduce the size of the created sprite, and still have all the
   necessary detail present in it, produces a sprite which uses up most
   of the free memory available in your machine. This may mean that
   you have difficulty utilising the sprite in other programs.
   eg. if you wanted to add some text lables to the sprite image and then
   to place the combined sprite plus tables diagram into the middle of a
   page of text in a word processing program before printing out a copy
   of the page, you could find that once the word processing program
   has been started up and grabbed the amount of memory it needs to
   run, there is then insufficient free memory left to load the sprite file
   into the word processing program and print it out.

   In this situation you may well still be able to generate the desired
   printout if you proceed as follows.

   Ensure that you  save any files you have been working on, then reset
   your computer (press ctrl break) to ensure that you have no
   unnecessary modules taking up space in the module area.
   Load the KnitConv program onto the icon bar.

   Create as large a sprite as memory will allow and save it to a disc.
   Quit the KnitConv program then load the ChangeFSI program
   (supplied with your computer) onto the icon bar.

   Use ChangeFSI’s sprite scaling routines to reduce the size, and thus
   the memory requirement of the sprite created above.

   ChangeFSI’s sprite scaling routines are much more sophisticated than
   those used by KnitConv. They do take into account the information
   available in all the rows of the input sprite to produce a dithered
   output sprite. This dithering process is much more efficient at
   maintaining the fine details in a sprite image which is being created at
   a reduced scale.

   The dithered sprite produced by allowing ChangeFSI to reduce the
   size of the sprite on the disc is more likely to have survived the
   scaling process intact whilst its memory requirement will have been
   reduced, perhaps by enough to allow it to be combined with the text
   and printed, than would have been the case if the scaling had been
   performed solely by KnitConv.

   There is of course still a limit to the amount of reduction possible
   without loss of image detail but ChangeFSI should produce better
   results in this regard than KnitConv.


                 ***Scaling a sprite using ChangeFSI***

   Ensure that you have a copy of the sprite file to be scaled visible
   in a filer window on the screen.

   Locate your copy of the ChangeFSI program and load it onto the
   icon bar by double clicking on its filer window icon.
   Press Menu over ChangeFSI’s icon bar icon and open the Scaling
   submenu by moving the pointer off to the right of the arrow from
   the Scaling menu option.

   Click on the Custom button to ensure it is selected then enter the
   scaling setting required. eg. to reduce the size of the input sprite to
   one third the size of the original, the Scaling dialogue box should
   look something like this:

                       <insert diagram 3>

   Open the Processing menu option and ensure that none of the
   options in the Processing dialogue box are ticked. If any are ticked,
   clicking on them using the Adjust mouse button will untick them
   whilst keeping the menu structure open.

   This ensures that the sprite does not undergo any transformations
   other than the scaling required.

   Open ChangeFSI’s Sprite Output dialogue box and ensure that the
   Colour button is selected.


                      <insert Diagram 4>

   Tick the Old mode option and type in the mode number the sprite to
   be reduced was created in. ( this can be found by loading the sprite into
   Paint and pressing Menu over the sprite file window which opens then go
   off the Sprite ‘sprite’s filename’ option then off the Info option ).
   All of the necessary options regarding how we want the input sprite
   to be processed by ChangeFSI have now been set so drag the sprite
   file icon of the sprite to be reduced from the filer window to
   ChangeFSI’s icon bar icon.

   This will cause ChangeFSI to process the sprite file and open a
   viewing window containing the reduced sprite on the screen.
   If the input sprite has been reduced successfully with no loss of detail
   then pressing menu over the viewing window to open the Save
   Image submenu will allow you to save the new sprite file to your
   filer window.

   If the viewing window reveals that the input sprite has been reduced
   too far and has lost some of its gridlines then open ChangeFSI’s
   Scaling options dialogue box by pressing Menu over ChangeFSI’s
   icon bar icon and going off the Scaling option and alter the figures
   to  reduce the amount by which the input is scaled. eg. 1:2 instead of
   1:3

   Then click on the Reprocess option in ChangeFSI’s icon bar menu
   to replace the sprite in the viewing window with a new version
   created using the new scaling factor.Each time the Reprocess option
   is chosen, ChangeFSI reloads the sprite file from the filer window
   and creates the contents of the viewing window using the currently
   set processing options.

   This process of altering the scale setting in the dialogue box then
   clicking on Reprocess to make the changes take effect can be
   repeated as many times as necessary until you have created the
   smallest possible sprite which still contains all the image data. Then
   you can save the result from the menu available in the viewer
   window.


                           ***Jacquard processes***

   The input block is created as a block of cells, 24 stitches wide, (the width of the
   punchcard), and in this case 14 rows high. It is important to design the block carefully
   so that when it is repeated above or below, and if necessary to either side as well, the
   pattern created meets and is continued across the join correctly. see diagram 5, or
   load the file PatBlock1 into EasyKnit to see an example of a suitable block.

                          <insert Diagram 5.>

   Any unfilled rows at the top of the block (rows 15-20 in this example)
   are ignored by the Jacquard conversion process but for accurate
   translation, the block must start on the bottom row of the grid and
   contain no unfilled stitches.

   As an example of the result of analysing a pattern block using each
   of the Double Jacquard translations available, this block will be used
   as the input file for conversion using each of the available translation
   methods in turn.

   *Double Jacquard pattern using Standard method.*

                       Input Block
                    <insert diagram 5>

   When analysing the input pattern block to create a Standard double
   Jacquard pattern the program looks at the bottom row of the block,
   and finds the sequence in which the colours appear.

   This sequence is repeated in the same order throughout the analysis
   of each row of the input block.

   The program  recreates the stitches of the first colour in the
   sequence as the bottom row of the pattern. It then repeats this row
   as the second row of the pattern.

   The program then uses the next colour in the sequence and
   reproduces the stitches of that colour as rows three and four.
   The program works through the sequence of colours in turn
   producing two rows of pattern for each colour. If there are no
   stitches of the colour currently under consideration, the program
   puts two blank rows into the pattern.

   When all the colours in the sequence for the bottom row have been
   separated and recreated, the program analyses the next row of the
   block and separates each of its colours in sequence working from the
   bottom to the top of the block.


   Double Jacquard output pattern using Standard method.
   <insert Diagram 6>


   *Double Jacquard pattern using Elongated method.*

                    Input Block
                 <insert diagram 5>

   When analysing the input pattern block to create an Elongated
   double Jacquard pattern the program looks at the bottom row of the
   block, and finds the sequence in which the colours appear.
   This sequence is repeated in the same order throughout the analysis
   of each row of the input block.

   The program recreates the stitches of the first colour in the sequence
   as the bottom row of the pattern.

   The program then uses the next colour in the sequence and
   reproduces the stitches of that colour as row two.

   The program works through the sequence of colours in turn
   producing one row of pattern for each colour. If there are no stitches
   of the colour currently under consideration, the program puts a blank
   row into the pattern.

   When all the colours in the sequence for the bottom row have been
   separated and recreated, the program analyses the next row of the
   block and separates each of its colours in sequence working from the
   bottom to the top of the block.

   When in use, the knitting machine’s Elongate button is set so that the
   punchcard is advanced every second row.

   This produces an identical method of knitting as a Standard Jacquard
   pattern but requires only half the number of rows of punchcard to be
   punched out.

   Double Jacquard output pattern using Elongated method.
   <insert diagram 7>


   *Double Jacquard pattern using Jigsaw method.*

                   Input Block
                <insert diagram 5>

   When analysing the input pattern block to create a Jigsaw double
   Jacquard pattern the program needs to know which of the colours
   used in the block represents the background yarn colour.
   The input pattern block is considered in pairs of rows working from
   bottom to top. The sequence order of the non-background colour
   stitches for the first pair of rows is determined.
   The program recreates the stitches in the background colour from
   the bottom row of the pair of rows of the block as the bottom row of
   the pattern.
   It then uses the first non-background colour in the sequence
   determined for this pair of rows and recreates the stitches of that
   colour from the bottom row of the pair as the second row of the
   output pattern. The stitches of the same colour from the top row of
   the input pair is then placed in the third row of the output pattern.
   The next colour in the sequence is selected and the stitches in that
   colour from the bottom row of the input pair form the next row of
   output, followed by the stitches from the upper row of the input pair.
   When all the non-background colours used in the input pair have
   been analysed and transferred to the output pattern, the background
   colour stitches from the upper row of the input pair are placed in the
   next row of the output pattern.
   This completes the analysis of that pair of rows from the input block.
   The next pair of input rows are then analysed in a similar manner
   until the top of the input block is reached.
   If there are no stitches of a particular colour used in one of the pair
   of rows under consideration then a blank line is added to the output
   pattern in place of the missing colour.
   The order sequence in which colours are used is determined
   separately for each pair of rows and is therefore not a constant
   repetition throughout the output pattern but follows the order as
   determined by the input pair under consideration.
   Input Block

   Double Jacquard output pattern using Jigsaw method.

             <insert diagram 8>

                                           THE END