Category: Color reductions and dithering

Online Pattern generators, hacks, free KM manuals, and more

I welcome being contacted re any problem links
generators that require color changing every 2 rows using a color changer (or 2 carriages)
the generator used by Fabienne  http://fabienne.us/tag/knitting/
other generators that can help with shaping garments, or some basic knit motif design
knitting pattern http://kpg.sourceforge.net
top-down circular raglan calculator http://kpg.sourceforge.net
Icelandic round yoke design does not work any longer in later version browsers, on Mac even with the installation of Silverlight, on Ravelry, it was noted the program does operate in internet explorer http://knittingpatterns.is/#/Design
charts: lace, cables, and more http://chartgen.orangellous.com
reducing black and white images to repeats sized for punchcard machines http://oknitme.serpicanaro.org/
punchcard generator and how to use videos from knit labo ??
math calculators for knitting
http://www.getknitting.com/ website closed 
free online manuals, magazines
hacking
a hacking history https://www.beautifulseams.com/2014/10/29/tricodeur-writeup/
only the intro is in German: a nearly hour-long presentation by Fabienne
another approach for Brother models KH”‘930, 940, 950i, and 970: http://daviworks.com/knitting/ and the associated group on Ravelry 
970 how to hack instructable 
for additional cumulative information, software compatibility and hardware specs see Claire Williams’ website
GitHubs
PatternUploader
color reductions/ conversions for large, nonrepetitive images Mac
online generators
photoshop tutorial
pattern generators/ web design
open-source charting program http://sourceforge.net/projects/sconcho/
quick screenshot

1/21/2016: Online weaving program by Andrew Glassner ; associated blogpost 

11/26/17 a simple, user-friendly free motif design paint program for Mac, last updated April 2019: Paint Brush

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

…

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 color reductions for 2 color “portraits”

The many faces of Rocco

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_Greyscale

Colors_Desaturate_OK

rocco desaturated, in “knittable portrait size”

using edge detection and its algorithms

Difference of Gaussians

what happens if in addition color_ invert is used with Roberts

adjusting B/W with Threshold

after 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

From the Gimp manual: image conversion to indexed  and color map dialogue 

As for camera portrait apps: Snapdot (originally 1.99, free in 2018) will render dotted “artworks”

I had no luck reducing this to one bit recognizable 1-bit B/W in PS, but here is the GIMP version in “knittable ” size

Hyperdither 150X154  pixels

Onebitcamera, another fun tool, has not been updated for the latest versions of Mac OS and associated devices

5/4/2019 Other than GIMP: after straightforward load, convert, save, with no other adjustments, images shown in approximate 150 pixels/sts in width, no significant change results with conversion to color B/W indexed
http://gazs.github.io/canvas-atkinson-dither/
https://29a.ch/2016/08/04/ditherlicious-1-bit-image-dithering
and using the same software, slightly different settings

GIMP tutorials on edge detection
http://www.learnerswings.com/2014/05/how-to-use-edge-detect-function-in-gimp.html
https://visihow.com/Detect_Edges_in_an_Image_in_the_GIMP_Application
https://docs.gimp.org/en/filters-edge.html
https://www.youtube.com/watch?v=wf6bs_vW1IU

Dithering explained 

From a 2013 post, I no longer have the program available to me: Photoshop offers a myriad of additional options for converting images between color modes see help.adobe.com   diffusion, halftone, pattern, custom

Color reduction/conversions, Mac Os

A recent forum post brought up the question that rises periodically on how to reduce colors in photographs, scans, etc. so as to be able to in turn use the image in a low-resolution medium such as knit. There are very many ways to achieve this. The post had specifically asked for low cost or free alternatives using Mac software, so I began playing, and compiled the following document detailing some of my processes, addressing large scale, non-repetitive images in Color reductions for knitting. The document samples were simple, straightforward conversions, with no further “tweaking”.

Mac Os: iPhoto, Preview, further software downloads:

Free:  img2trak, HyperDither, XnConvert

99 cents One bit Camera
an option for Mac users, Bitcam

Free to try, $39.95 to buy GraphicConverter, the developer site
diffusion, halftone, pattern, custom A tutorial for owners of Photoshop   diffusion, halftone, pattern, custom With thanks to my test subjects: RoccoOne bit camera and my sofa fabric

An online service that will do the conversion for you: Knitpro, and a free service GitHub May 2019: ditherlicious

A later post on the topic, showing the many faces of Rocco