Category: Color Separation for Knits

Charting knits using Mac Numbers: color separations 1

A lot has been written on the use of excel in knit charting, I don’t believe there is anything “out there” on doing the same with Numbers. After my latest OS upgrade, I thought I would revisit playing with the updated program. This is not a tutorial as such, just a sharing of some results and observations on this particular effort. For the design, I used the same motif as in the last post on 2 color drop stitch on Japanese machines. Under the table menu, there is an option to split rows or split columns. This can be achieved in any selected area, without affecting the remainder of the spreadsheet. Copying and pasting the split image over an area of full-size cells will change its format, and in turn, allow for splitting again. In the image below A is the original motif, B the first split after selecting only those colored cells, C repasting B in an area of full-size cells, D selecting and splitting C to achieve elongating the original motif X 4.

to separate the colors for the 2 color drop stitch using white “erase” every other row: these rows will result in no pattern selection, and will be the rows on which stitches are dropped. Select and copy and paste again. Choose either of the 2 colors and white-out that color (I chose to start with cyan) on the first and then every other colored combination row. Note there are 3 blank rows between each “erasure” after the first. Once the process is completed to the top of the design, select, copy, and paste again. On alternate rows that are still in 2 colors, the magenta can now be whited out, and this repeat when complete, visually be checked for any errors. Colored squares remaining in either color now translate to punched holes or black squares on mylar depending on the size of the original motif

This particular method works on even motifs with an even number of colors, as splits double existing rows. Row and stitch numbers, text, etc may all be added. The image below does not refer to color separations. It illustrates the ability to go twice as long, twice as wide through using splitting rows, and in turn, splitting columns. Twice as wide used alone comes in handy for any knitting on every other needle, sometimes used for thicker yarns on the standard machines that do not have the ability to do that via electronic programming.

WordPress will not allow uploading a numbers document; here is a numbers document exported as excel .xls  that should open in Numbers on a Mac for anyone wanting to play with charting a bit. The extra color square on the far right is a “place holder” of sorts, needed to avoid cropping of all empty cells to the right of the motif in the software’s exporting the file  numbers_test_doc

4/30/2018: the feature described below in 2012 disappeared from later versions of numbers, I am presently using version 5.0. Later versions offered these options for working with rows and columns. The highlighted row will be duplicated, a slower process than simply splitting cells. A positive feature is that an individual table may be changed while still within view on other tables on a single sheet, without globally affecting the document. 

While playing with more table options today I sorted out a way of creating blank rows between design ones, possible charting uses still TBD. Though the results from such charting are not capable of being downloaded directly into knitting software, they are a good way to sort out repeats and begin to understand and create any necessary color separations. By holding the command key, rows on the table can be highlighted and hidden as a group. I chose all the even-numbered rows. The repeat then is drawn. When it is complete, rows originally targeted for hiding are “unhidden”, leaving the design motif with a blank row between each design row, at twice its length. Hiding could take place at irregular intervals as well. 

December 8, 2012: in writing my latest post I found an easier way to deal with split rows and columns. If the motif area is copied and pasted on a “blank” part of the spreadsheet a new table is created, which can be altered without concerns about affecting the remainder of the document. It’s like working with small pieces of graph paper rather than a very large one. The motif area is chosen and pasted, creating a new table

the table, split into row option is used

simply select all, click on the line at bottom of any numbered, grey row cell on the left of the table, and resize to match the remainder of your document, when the desired measurement is achieved, release the mouse and the document cells will be uniform in size.

the same process may be applied to split columns, may well have to try this on some of my huge excel charted spreadsheets

Drop stitch lace, 2 colors per row, japanese machines

This is an attempt to duplicate the results of Passap tech 185 used in knitting multiple colors per row drop stitch “lace” fabrics.
The method may also be used for more colors per row, expanding the repeats accordingly to the number of colors per row X 2 for each motif row. For example, here 2 colors per row are expanded to 4 rows for each color in length, 3 cols per row would need to be expanded to 6 for each design row.
This fabric widens considerably when completed, so at the top and bottom edges, cast ons and bind offs, need special consideration and planning.

In this instance, the design has been separated for the dbj method wherein each color in each design row knits twice. The second row in each pair of rows is then cleared of any pixels which results in no needle selection, providing an opportunity for the loops formed on the main bed to be dropped with the assistance of a stitch ditcher.
The fabric may also be executed using the original separation, but the opportunity to use an accessory to facilitate stitch dropping is lost’
The method for swatching: cast on for every other needle rib, knit 2 circular rows followed by one row of all knit rib, and transfer all main bed stitches to the ribber. For an open stitch cast on directions and photos see later post.
COR Set up needles on both beds for every needle rib with an extra needle in work at each end on the main bed, cancel end needle selection (KC II). With the main bed needles in the B position, set the knit carriage to slip in both directions so as not to pick up loops across the whole row as the first pass toward the color changer is made, needles will be preselected for the first pattern row
COL: the ribber remains set to knit every needle, the main bed to slip in both directions. A piece of tape in front of needle butts of needles in A position aside from the edge needles in work helps keep from accidentally moving extra needles into work when dropping whole rows of stitches
change color, as the carriage moves to the right, selected needles will pick up loops on the main bed that will form the long stitches when dropped, while the next row of pattern is selected, so by the time the carriage has reached the right side of the machine, needles will have flatlined due to the all blank rows in this type of color separation
COR: use any convenient tool to bring all needles involved out to E, and use the same tool to return all stitches back to the B position, dropping the loops on the main bed which will form the long stitches. With this type of color separation, it is also possible to use a modified Studio P slider Directions on altering the studio tool for use on Brother machines to drop stitches from right to left before continuing to knit.
Check that all needles are empty and that loops free and between the beds.
As the carriage moves to the left again toward the color changer, the ribber only will knit all stitches (does so every row), needles will be preselected for the next row of long stitches, selected needles are not knitting.
Colors are changed every 2 rows
The pattern and the “color separations”, were achieved using GimpImages from left to right
1. motif  lengthened X 4
2. every other row erased (non-selection rows)
3. 2nd pattern row (every other row of design now left) color inverted
4. pattern marked in 5X5 blocks for easier tracking when drawing on the 910 mylar sheet
A downloadable PDF of basic info 185_brother
sideway views: knit side purl side The emerging pattern can be seen, and to be noted is the elongation factor involved as in many color separation DBJ fabrics
For a later review of cumulative posts on the topic see: revisiting drop stitch lace 
For the design method for staggered shapes in drop stitch see Ayab software-related post.
In other electronics, a single repeat in both height and width is adequate and machine selections will determine whether the design is knit as a single motif or as all-over patterns.
Ayab’s preselection is always from left to right. In unhacked 910s, the first preselection row can be from right to left, so no accommodations need to be made for shifting the last row to the first of the design repeat.
For machines accepting electronic downloads, program the repeat with the first design row containing black squares in it, and adjust the spacing between repeats as preferred. This particular version is 80 stitches wide In an unaltered 910 with the ability to double the width of the programmed repeat, mylar users are not excluded from exploring a similar fabric. The repeat above may be rescaled to half the width,  drawn that way, and then use the twice as wide built-in feature. In Gimp scaling this design to half-width, note the right side of each repeat contains an odd number of squares, the left side an even one. The repeat may be used as-is or redrawn, adding or eliminating black squares if symmetry in each shape matters. The free program Paintbrush produces the same image, mirrored.
The explanation: further analysis of the original design reveals the fact that some of the pixel numbers in the design black square blocks are uneven in width. In this instance, 3.5 is half of 7, and half pixels cannot be rendered, so the software assigns the split to 4 and 3.
A Passap sample

From lace chart to punchcard 6, to electronic

The chart here is simpler than those previously explored, appeared in a Japanese publication, was suggested for use in MK as a hand technique

The lace transfers are in pairs, alternating in direction; this excel chart assigns symbols and colors to them. The repeat is 8 stitches wide, 10 rows tall, which make it suitable for punchcard machines as well as electronic ones

Below is the expanded graph, with alternating transfers for each row, and 2 knit rows completing each sequence. I am now using Studio mylars on the 910, so the additional border markings are to help orient the black squares on the mylar’s markings (6X5 as opposed to Brother’s 5X5). The expanded chart, now 40 rows in height:

On cards, orange and green may be punched as shown. Below is the resulting swatch, knit on 910 with #2 button up (flipped horizontally). 1: dropped stitch joy, which could actually be easily repaired at this point. 2: a partial repeat creating an interesting edge, more successful than the opposite side, a result that bears testing in swatches. 3: bind off around 2 gate pegs for maximum stretch in any blocking.

From hand knit lace chart to punchcard 2

Following up on the previous post, from-hand-knit-lace-chart-to-punchcard-1, a 24 stitch chart with marked in symbols for conversion to MK repeat: a 24 stitch chart with marked in symbols an isolated repeat segment worked out on a striped template after choosing and marking the transfer direction of the eyelets on the original, green for to the left, yellow for to the right,  marking lace transfers rows for a partial card segment,  the numbers on the left reflect LC passes and their direction is marked by arrows, the numbers on the far right reflect those indicated on a factory-issued blank card, being selected seven rows below eye level by the reader.
DIY offers the opportunity for extending designs, here another lace transfer segment is added, a card would repeat the design twice in width, and twice in height, again showing the shift necessary when marking rows for cards,  The full punchcard for the elongated repeat, with a punching error marked by the red spot, also used to indicate the corresponding spot for the transfer error in that needle spot on the corresponding swatch

From hand knit lace chart to punchcard 1

I have posted previously on lace punchcards, their use, and traveling between machine models. There is extensive documentation in manuals and literature on the mechanics of their patterning. This series will attempt to follow my most recent post and to visually address the transitions from a charted repeat to a corresponding punchcard.

The illustrations may apply to machines that use two carriages for lace, Brother/KNitking, and some Toyota. other than simple lace on both Brother and Studio machines by altering the placement of the first selection row on the respective punchcards.

The sole function of the auxiliary lace carriage is to select and transfer stitches. The passes required to execute the transfers for one pattern row are known as a transfer sequence. Since the lace carriage is always set to read the card, every pass needs to be programmed in the card and electronic patterning.

Each time transfers are required it takes two or four passes (more for multiple transfer lace) to preselect the needles, transfer the stitches, and return to the left side.  One pattern row on the chart will need expansion (akin to a color separation) into passes necessary to execute the transfers for each sequence. The lace carriage will always activate the card reader, so every pass must be reflected on the card. This accounts for the familiar arrow markings on the left of factory pre-punched lace cards.  Selection, positioning, and return passes are blank rows on cards, resulting in no needles being selected. No selection rows may serve as a reminder to switch carriages. It is best to begin with simple charts to sort out the process. For punchcard machines, the stitch repeat must be a factor of/divisible evenly into 24. Color-coding eyelets for left and right transfers may help. In multiple transfer lace, two or more adjacent stitches are transferred to the right or to the left, creating an eyelet group. On the knit side the group will lean away from the eyelet. The lace carriage is not capable of multiple transfers at one time, so each stitch in a group will require a separate pass. Within each group, the lace carriage must transfer the stitch farthest away from the eyelets first.

Some simple transfers, graph markings on left, expanded for punching on right

the symbols key for this post a multiple transfer stitch charted for machine knitting location for holes, and directions for lace carriage transfers on the next row the punched card and associated actions going wider, and combining different size motifs the expanded version An alternative way of working: colors are chosen for horizontal lines on which holes for transfers are placed, in the direction indicated by the inspiration chartThe equivalent mylar repeat

Atkinson dither github (free)

I have linked before (March 14, 2013) to this github as a way to achieve atkinson dithered images for possible use in knitting. I received a post with questions on how to achieve this successfully. I work on a Mac, latest OS. The resulting dithered files were not read when downloaded by any app other than Preview, and resizing within program was poor quality. Here is my work-around: it is always best to resize any of the images to be processed in color or grey scale, before indexing modes or dithering. Once that is achieved, import image into github without changing output size in the program itself, and download. Your own image size will be retained. Now time for another freebie intervention: XnConvert will accept the file, convert it to BMP or other readable formats if preferred, resulting in a knittable image.

the sized image

hyperdithered.png

via github_XnConvert_.bmp

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Converted images,”representational knitting”

One bit camera “snaps pictures in digital retro style. I began this tale with a partial shot of my face. The app apparently is no longer available via US App Store (11/15/2017)

resized, greyscale, knittable size bmp

The old bag of tricks did not produce an image I was happy with, I finally used Ggraphicconverter Picture_Mode_ Bitmap for my downloadable file

Migrated from Mac to a PC laptop, opened in WinCrea, the image repeat was downloaded to Passap, program tech 179. The bottom  of the swatch is knit single bed LX (slip stitch), the top is double bed, back bed set N/N, same tension throughout, the middle stripes are operator error in forgetting to make the lock change to LX on the front bed; the gauge is significantly and obviously different

Moving on to a birds’eye backing, the bottom starts the pattern with dark color, top with light (another operator error and a reminder to keep notes even for what may seem obvious); the black is slightly thinner than blue resulting in a change in gauge once again

The bouncing gauges certainly indicate some of the problems in maintaining aspect ratios in representational knits. The best solution may be to do a large swatch in the planned technique that is at least 100 sts X 100 rs in chosen yarn and then adjusting image aspect ratio before knitting the final piece, which in turn may be better done before conversion to final BMP and require repeating the process from its beginning.

For separations such as technique 179, and those by default in Japanese machines for 2 color DB, images must have an even number of rows in length. My original image crop was 73W by 85L pixels, so I had to shorten it by one row, which was actually achievable within WinCrea. The single bed FI swatch measured 7 inches in width, the double bed ones 12 inches at their widest point.

Last but not least, here is my friend Rocco processed via Hyperdither, Mac to PC, to WinCrea, to Passap and knit 150X150 pixels/ stitches

May 24, 2019 a greyscale mode scaled image processed in ditherlicious online produced a sharper, far more defined image than my previous effort 142X146 pixels

for more Rocco “portraits” see post

GIMP and dithering color reductions for B/W “portraits”

The many faces of Rocco: in my 2013 tests in Gimp, the image is 150 pixels wide by 154 pixels high  The image is used with the kind permission of Rocco’s owner. I have used this image before, when I posted previously on some ways to reduce colored images to B/W for possible knitting using a Mac computer, please see post on 013/03/14/ color-reduction- conversions-mac-os/. Gimp offers some alternatives to the familiar dithers and is available, free, for both PC and Mac platforms. Tutorial links on Gimp edge detection available online as of May 2019 are listed at bottom of the post.

Image_Mode_Indexed_ one bit black: immediate result, too dark

Threshold adjustments may not be made in indexed images to alter the above image, so it’s back to greyscale. Reductions to greyscale may be achieved through Image_ Mode_ Greyscale or choosing Colors_Desaturate_OK options. Desaturation offers additional choices

Image_Mode_GreyscaleColors_Desaturate_OKRocco desaturated, in “knittable portrait size”using edge detection and its algorithmsDifference of Gaussians

what happens if in addition color_ invert is used with Robertsadjusting B/W with Thresholdafter a bit of “tweaking” Image_Mode_Indexed, rendering it “knittable in 2 colors” getting silly with filling the ground with pattern behind the floating head

2021: the latest, December 2020 updated version of Gimp for Mac OS
Gimp dithering controls easily accessible with mode changes to indexed I found I got the best results adjusting the contrast in the original greyscale image prior to changing its mode to indexed and dithering (Floyd_Steinberg, normal)  Dithering options in Gimp 2.10 may be found at the bottom of the colors menu This filter can reduce the number of colors in an image by reducing the levels per channel (colors and alpha). Different dithering methods can be specified to counteract quantization-induced banding.
Presets are common features for many Colors commands.
Red levels, Green levels, Blue levels, and Alpha levels sliders set the number of levels for the respective red, green blue, and alpha channels.
Dithering method: can specify the dithering method to use
None: no dithering will be performed
Floyd Steinberg: the most commonly used method of dithering, and the default for this filter
Bayer: the algorithm is characterized by noticeable cross-hatch patterns in the result
Random, random covariant: use randomization of the pixel values to reduce the number of colors
Arithmetic variants are based on magic numbers and arithmetic
Blue noise variants are sometimes thought to be the least distracting
Random and new seeds are two random dithering methods.
When converting to indexed colors with the image unaltered, and using positioned dithering, the last option Hyperdither: options offered  default Jarvis
default Stucki
online, options https://ditherit.com it is possible to choose from multiple palettes Sierra dither

5/4/2019 Other than GIMP: after straightforward load, convert, and save, with no other adjustments, images shown in approximately 150 pixels/sts in width, no significant change results with conversion to color B/W indexed
http://gazs.github.io/canvas-atkinson-dither/
online, default settings https://29a.ch/2016/08/04/ditherlicious-1-bit-image-dithering
Check dithered results, downloaded images may be in RGB Mode. Prior to any knitting, they will need to be converted to B/W indexed.
Looking for ways to reduce the noise in dithered images I tried this conversion in XnSketch, using the photocopy effect,  beginning with the colored image of Rocco, the results: imported the result into Gimp and saved it in indexed  2 color BW and in turn, 3 color indexed mode, no color adjustments, finding the result pleasantly simple beginning with the greyscale generated image followed by Mode changes in Gimp, indexed 2 color BW, then indexed 3 color, there appear to be very subtle differences with a bit more detail: Another online resource with an extensive array of dithering options https://app.dithermark.com. Here are 2 conversions using the app, the images are 2 color B/W. The presence of a third color is an illusion created by the difference in the distribution of BW color pixels, they loaded fine as viewed for knitting in Ayab, and in img2track, once I remembered to change its setting to 2 color knitting from the last used one at 4 colors It is possible to reduce images to 4 or 3 colors using the program as well: a slider for color count is used to choose the final number of colors in the reduction. Again, these instances have no added manipulation A series of dithers:
To retain the quality and size of the dithered image, download it, rather than using a screen grab. The software used to separate the chosen dither may alter the result somewhat. I am writing my posts using an iMac M1 with OS 12.0.1. At this point Ayab is not operable, img2track does open images, but in this case, with interesting distortions, and it does not download any files at all. Yet another dithering tool, allows one to draw in dithering mode using a variety of patterns and will dither images. In the latter instance, there is no real opportunity to tweak or alter the result shapes drawn using a few of the large variety of offered patterns: 

2023 working with pattern fills and removing any background 

In this instance, a portrait of a dog wearing a sweater image was generated in Midjourney and scaled to 191X195 pixels.
Dithering online apps were used to reduce the colors in instants to 4, 3, and 2.
The greyscale image was also color reduced and dithered in Gimp.
All results were not adjusted further in any way.
Color reductions could be tweaked a bit further prior to actual knitting.
Magnifying the chosen individual result will help visualize the change in resolution quality of the image in the final knit piece.

 

More GIMP charting 3

These are quick notes from some of my continuing experiments, not explicit how-tos or item patterns. Possible lengthening of designs dependent upon knitting technique is not considered; the “charts” were created keeping the aspect ratio of the original motif. The initial images are copyright free.

from scanned B/W source, 200 pixels X 227

open document

Image_Mode_B&W 1 bit indexed_ Convert

Image Scale 200 wide down to 50

areas were “cleaned up” using single-pixel pencil, when satisfactory capture window with grid enlarged for working graph,  or remove the grid, export in format for download

this is a partial repeat of a large black and white .png image

working with a smaller, random selection

Open image

Image_Mode_B&W 1 bit indexed_ Convert

enlarge, show grid, decide on the accuracy of repeat,  when OK, graph or export and knit, no clean up required for this one

Filter_Map_Tile_magnifying result  will test the accuracy of the repeat

the motif was a random crop, with obvious issues, more work would need to be done with the original image to isolate the proper section for tiling accuracy to occur

a multicolor image 143 pixels X 112

Image_Mode_Indexed _3 color (manual change from 4 to 3)

Image scale to 100 pixels wide

Enlarge for viewing grid and/or cleaning up; result yields 2 repeats that could be used 50 sts wide each, leaves could use a bit more detail

a partial image grab, pre any “corrections”

if color separations are needed for software that can superimpose colors and do the necessary color changer manipulations cues a link on color separations for screen printing provides some ideas. Another method

Tools_Selection Tools_By Color Select

Edit_Copy

Create new document the same dimensions

Edit_Paste

repeat for each color

the results: the flower is actually in the “wrong place” even with what appeared to be the same document settings

easier and “on the spot”:

Tools_Selection Tools_By Color Select

Click on color one (flower)

Edit_Cut

Fuzzy select, click on the screen outside of the image: the result

Re-open original image

Tools_Selection Tools_By Color Select

Click on color two (leaves)

Edit _ Cut

Fuzzy select, click on the screen outside of the image: the result

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Double jacquard separations 4_ making them “work”

Working back to the repeat from post # 3 on this subject, I returned to the drawing board and edited the separations.  Tetris is a tile-matching puzzle video game originally designed and programmed by Alexey Pajitnov in the Soviet Union. The objective of the game is to manipulate tiles, by moving each one sideways and rotating it by 90 degree units, with the aim of creating a horizontal line of ten blocks without gaps. The principle at use for the separated “squares” shapes is to achieve the same result for each of color separation groups (highlighted by dark borders in the charts), by moving them up and down, or changing their positions in the color sequence. The first method (beginning with only one row of ground color) has eluded me in terms of an “error free” result. More than one version consistently in a missing single stitch of color. The latest method shows the problem color “tiles” marked in dark ovals. The column on left is the original separation, A shows the juggled colors, B the pixels, squares, or punched holes for the repeat, and the far column on the right shows markings that may be used to track the color change sequences, which may be transferred to punchcard, mylar, or for any cues in change of sequence your program can provide. The swatch approaches the original intended design far more than any of the previous attempts. It is expected that the background color will be the majority or main color of the design; it gets separated out as first color. By splitting the knitting of most of the needles to the beginning and the end of the sequence (japanese 2 color default) this way, one supposedly eliminates the chance that the needles knitting the second row of each color will knit over, blocking a space yet to be knit in the first row of the design by a color that has not yet been knit. In this small pattern no colors knit more than 3 consecutive stitches at any one time. With some motifs the final alternative is to redesign the motif.

the test swatch (striping was the result of forgetting to set the KM for slip <—>)

Using the alternative method for decreased elongation of motif upon knitting, here are the working charts for beginning with 2 rows of color 1

the swatch: got it!

my mylar sheet markings

A&B show my marks corresponding to color positions in the color changer, the first 3 repeats on left are the ones used to knit  the swatches. Separations are suitable for DBJ, but I chose to knit trials in single bed slip stitch.

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