Why colors have to be reduced

An embroidery machine can only sew areas of solid color, and every color in the design is one thread color. A photo, or a logo saved as JPEG, contains thousands of slightly different shades. Before your image can be turned into embroidery, it is therefore simplified to a small number of flat color areas. This step is called color reduction.

These settings control this step, each at a different point:

• Background detection (on in the default preset) makes the background transparent, so it is normally not embroidered.
• Pre-smoothing prepares the original image so that better colors are found.
• Target number of colors decides how many thread colors the result may have.
• Noise/dithering cleans up the reduced result by removing specks and scattered pixels.
• Thread table (optional) replaces the colors with real thread colors and adds the thread information to the embroidery file.

Scaling sets the embroidery size. It does not change the colors. Embroidery parameters decide how the result is turned into stitches.

Checking the result: click Optimize to preview the color reduction. The preview appears under Server result. Number of thread colors shows how many colors the result has, and you can compare it with Number of colors under Working image. Create embroidery data always starts again from your original image with the current settings, so you can change the settings freely before you create. Optimize and Create each use license quota.

Entering values: use the slider or type a whole number into the box. A decimal value such as 7.5 makes Optimize and Create fail. If the Target number of colors box is left empty, the result has only 1 color.

Start values: each time the ACE client starts, it loads the preset marked Default (load at start, read-only). The supplied default preset uses Target number of colors 12, Noise/dithering 5 and Pre-smoothing 5, so values you changed are reset after reloading the page. Exceptions are Skip color reduction, Background color (R,G,B) and the two options in the Settings (⚙) Color reduction tab: they are not part of the supplied preset and keep their last setting. To keep your own values, save them as a preset (see Presets):

1. In the Presets panel, replace the text in the Name field with a new name. At start it shows "Default", which is read-only.
2. Click Save, the first button below Name.
3. The new preset is now selected. Tick Default (load at start, read-only).

Target number of colors

Range: 1 – 24

What it does

This setting decides how many thread colors the result may have. The software analyses your image and picks the colors that represent it best, then assigns every pixel to the closest of these colors.

• More colors keep more detail and shading, but every extra color means another thread and more color changes on the machine.
• Fewer colors give a simpler, bolder design that is quicker to sew. Similar shades are merged into one color.

When you need it

This setting applies to every design. It is the most important control of color reduction.

Clean logos and photos behave differently

Clean artwork with flat colors (real vector graphics, flat PNG logos):

• The software recognizes the flat colors and keeps the original colors of the logo, as long as Target number of colors is at least the number of logo colors.
• In this case the setting is an upper limit. A logo with 4 flat colors usually stays at 4 colors even if you set 12.
• If extra colors appear along the edges, set the value to exactly the number of logo colors. For SVG and AI logos, also switch on Vector: no anti-aliasing (hard edges) (gear button ⚙ in the toolbar → Color reduction tab). See Vector: no anti-aliasing.
• If you set fewer colors than the logo has, the logo is treated like a photo. Similar logo colors are merged into averaged colors, and Pre-smoothing then takes effect.

Photos, JPEG files, scans and images with gradients:

• The software normally uses the full number of colors you set, and extra colors go into shades and edge pixels. Set exactly as many colors as you want to sew.
• The colors are averages of groups of similar shades. They may not match any single pixel of the original exactly.

How to count the colors of a logo

• Background: it does not count if it is transparent or removed by Background detection. If the background stays in the design, count it as one color.
• Preserve white highlights (e.g. eyes): if this option is on (gear button ⚙ → Color reduction tab), count white or very light parts as one of the logo colors. The option makes every very light pixel white. It takes one of your colors for white only if white would otherwise be missing; then one fewer color is left for the rest of the image. See Preserve white highlights.

Good to know

• Very small color areas are merged. In flat artwork, a color is kept only if it covers at least about 1/2500 of the motif (0.04 %). Smaller spots of color take the nearest main color, whatever target you set. Making the whole image larger does not change this; such a detail must be drawn larger in relation to the motif. To keep small white details such as eyes or glints, switch on Preserve white highlights (e.g. eyes). With the default Embroidery parameters they are then usually still left out of the embroidery; see Preserve white highlights.
• With a thread table: if you choose a table under Thread table (below these settings), every color is replaced by a real thread color from that table. Each color gets its own thread. If two colors are closest to the same thread, one of them gets the next-closest thread. See Thread table.
• 1 color turns the motif into a single-color silhouette in the average color of the motif (or the closest thread color). For this, the background must be transparent or removed by Background detection. Also switch off Preserve white highlights (e.g. eyes), otherwise white is added as a second color, and set Pre-smoothing to 0.

Recommended values

Noise/dithering (0 = off)

Range: 0 – 10 (0 = off)

What it does

This setting cleans up the result after the colors have been reduced. It removes isolated specks, scattered pixels and grainy areas in which one color is clearly in the minority, by giving them the color of their surroundings. The result has calmer, larger areas of color.

• No new colors are created, and the number of colors does not go down either. To get fewer thread colors, lower Target number of colors.
• The borders between larger color areas stay in place. Only sharp corners may become slightly rounded.
• The transparent background is not affected.
• A very regular 50/50 pattern of two colors, such as a fine checkerboard, is only worn away from its edges, and larger areas of it remain. For photos, Pre-smoothing can help against such patterns.

When you need it

Tiny spots of color are hard to embroider. They produce very short stitches, many jumps and unnecessary color changes. Use this setting when the reduced image looks grainy, speckled or noisy, which is typical for photos, JPEG files, scans and images with gradients.

How the values work

Every higher value cleans more. Small dots disappear sooner than lines of the same width:

Lines that separate two different colors, and outlines along a transparent edge, are kept a little longer than lines inside a single color.

Example, enlarged so that single pixels are visible. From left to right, the test image has scattered specks, lines 1, 2 and 3 pixels wide, dots of 2 × 2, 3 × 3 and 5 × 5 pixels, and a large area. It was cleaned with the same method the software uses:

Value 2 removes the specks, the 1-pixel line and the 2 × 2 dot. Value 5 also removes the 3 × 3 dot. Value 8 also removes the 2-pixel line and the 5 × 5 dot. Value 10 also removes the 3-pixel line. The large area stays unchanged in every case.

Watch out

• Fine details can disappear, even at low values. This includes hairlines, thin outlines, the dot on an "i", small eyes and small text.
• Narrow gaps can close. The cleanup treats every color the same way. A narrow gap between two areas of the same color, such as the space between two close lines or inside a small letter, can fill up in the same way a thin line disappears.
• The effect is measured in image pixels. The size of one pixel in the embroidery is the embroidery width divided by the image width in pixels. For example, a logo 600 pixels wide embroidered at 100 mm has about 0.17 mm per pixel, so a 3-pixel dot is about 0.5 mm. Embroidered at 250 mm, the same logo has about 0.42 mm per pixel, and a 3-pixel dot is about 1.25 mm.

Recommended values

Pre-smoothing (source, 0 = off)

Range: 0 – 10 (0 = off)

What it does

This setting smooths the original image (the "source" in the label) before the colors are chosen. It evens out noise, grain, fine texture and JPEG compression artifacts, which are blocky or fuzzy spots around edges caused by saving as JPEG. Edges between clearly different colors stay largely intact.

Because the software then works with a calmer version of the image, it finds cleaner, more representative colors and forms more even color areas. The smoothing only influences how the colors are chosen and assigned, so the result still consists of flat thread colors only.

When you need it

Use pre-smoothing for photos, scans, JPEG files and other noisy sources. Without it, grain or compression artifacts lead to blotchy areas or use up colors on noise.

It is not needed for clean logos and clipart. For images with flat colors the software uses the original colors, and pre-smoothing has no effect, as long as Target number of colors is at least the number of logo colors. If you reduce a logo to fewer colors than it has, set pre-smoothing to 0.

How the values work

Like Noise/dithering, the effect is measured in image pixels: the smoothing covers 3 pixels at value 1 and up to 21 pixels at value 10. It is therefore stronger on images with few pixels.

Watch out

• High values round off outlines and can merge small details with their surroundings.
• Dark edges: on images with a transparent background, including a background removed by Background detection, values from about 4 upward can make the colors along the motif's edge darker. The default preset uses 5. The effect is most visible on dark colors, and at high values on medium colors too. If an unwanted dark outline color appears, lower the value to 3 or less.

Recommended values

Thread table

Choice: - no thread table - or one of the thread series in the list

What it does

A thread table is the color chart of one thread series, for example Madeira-POLYNEON 40 or Amann-Isacord 40. If you choose one, two things happen:

• The colors become real thread colors. After the colors have been reduced, every color is replaced by the thread from the table that looks most similar. The preview under Server result then shows the colors of the actual threads.
• The embroidery file names the threads. For every needle, the file created with Create embroidery data stores the thread series, the color number, the thread weight and the manufacturer. The machine operator can see which thread to put on each needle.

With - no thread table -, the design keeps the colors found in your image, and the embroidery file contains only these colors, without thread numbers. The threads are then chosen at the machine.

When you need it

Choose the table of the thread you will sew with if you want a preview in realistic thread colors and an embroidery file with thread numbers. Keep - no thread table - if the thread is chosen later, or if your thread series is not in the list.

How the threads are chosen

• The thread that looks most similar is chosen, not simply the one with the closest RGB values.
• Each color gets its own thread. If two colors are closest to the same thread, one of them gets the next-closest thread. With very similar colors, this second thread can look noticeably different.
• The number of colors does not change. It is still set by Target number of colors.
• A color the series does not offer is replaced by the closest thread. Example: Madeira CLASSIC has no pure white; white areas become its lightest thread, 1003, a light grey.
• Small series have few colors, for example Madeira FIRE FIGHTER (24 colors), Gunold Polyfire (27), Madeira POLYNEON FR 40 (34) and Madeira CLASSIC 12 (45). With many colors in the design, some colors then end up on clearly different threads.

Thread information in the embroidery file

After Create embroidery data, the Thread colors button in the toolbar lists the needles of the design:

• Without a thread table, Color number and the text columns stay empty.
• The file stores the series and the color number, not the name of the thread color (such as "Ghost White").
• Series names longer than 15 characters are shortened in the file. For example, "Robison Anton Polyester" becomes "Robison Anton P".
• After Create, Number of thread colors is the number of needles. It can be slightly lower than after Optimize, because practically identical colors are sewn with one needle.

Watch out

• After changing the table, create again. The result shown keeps the previous table until you click Optimize or Create embroidery data again. Save embroidery saves the file made with the previous table until you click Create embroidery data again.
• Skip color reduction: the thread table is greyed out, but the selected table is still used when the embroidery is created. The colors are matched to the closest threads by a simpler method, and the thread information is written into the file. To create without thread information, choose - no thread table - before you tick Skip.
• Start values: the supplied default preset uses - no thread table -, so your choice is reset when the page is reloaded. To keep a table, save it in your own default preset (see Start values).
• "Garntabelle nicht gefunden" (thread table not found) after Optimize means that this table is not installed on the server. Choose another table or contact support. Create embroidery data does not show this error, and the design is then created without the color reduction settings. Check a newly chosen table with Optimize first.

Scaling

Scale (%) or Width (mm) / Height (mm); ↺ 100% restores the original size

What it does

Scaling sets the size of the working image. After Crop to image data the working image is your motif, so the size you enter is then the size of your embroidery. The three fields are linked: change one, and the others follow. The proportions always stay the same, so a design cannot be stretched in only one direction. Size under Working image shows the size you have set.

Pixel images and vector files behave differently

• Pixel images (PNG, JPG, BMP): only the resolution changes, the pixels stay the same. The size of the image is applied exactly. Enlarging does not add detail: every pixel simply becomes a larger piece of the embroidery. A logo 600 pixels wide, for example, has about 0.42 mm per pixel at 250 mm.
• Vector files (SVG, AI) that have not been cropped are drawn again at the new size, so they stay sharp up to about 690 mm on the longest side. The size is sent as a percentage, so expect a result very close to, but not exactly, the size shown. An SVG or AI file that only contains an embedded photo does not become sharper.

Where the 100 % size comes from

• PNG: from the resolution stored in the file. If none is stored, 96 DPI is assumed.
• JPG and BMP: always 96 DPI; a resolution stored in the file is ignored. A photo saved at 300 DPI therefore opens about three times larger than its print size. Enter the size you want. After opening, the status line shows the pixels and the DPI that are used.
• SVG and AI: the document size of the file. At 100 % the longest side is at least about 43 mm and at most about 347 mm; smaller or larger files open at these limits. An SVG that only wraps an embedded image uses the pixel size of that image at 300 DPI instead.

Good to know

• Crop first, then set the size. The size covers the whole image, including transparent or removed margins. Use Crop to image data first so that the size describes the motif, then enter the size. Cropping resets the scaling to 100 %. The steps are explained in Crop a motif and set its embroidery size.
• Minimum 10 mm. When you change a value, the design is enlarged if necessary, until its smaller side is at least 10 mm. The other side follows, so the side you typed can end up larger than you entered. Opening a file and ↺ 100% always give the original size, even if it is below 10 mm.
• Back to the original size: use ↺ 100%. An emptied field does not restore 100 %; when you leave it, the design jumps to the minimum size.
• The size is not saved. It is reset to 100 % whenever you open a file or crop, and it is not part of presets.
• Check afterwards: after Create embroidery data, Size under Server result is the measured size of the created design. After Optimize it only repeats the requested size.
• Noise/dithering and Pre-smoothing work in image pixels. For a pixel image, their effect in millimeters therefore grows when you enlarge the design. A vector file is drawn again at the new size, so for vectors their effect in millimeters stays about the same.

Watch out

• Skip color reduction: the scaling fields are greyed out and the size is ignored. The design then uses the resolution stored in the image (96 DPI if none). To get a specific size with Skip, save the PNG with the matching resolution (DPI) in your graphics program before opening it. The Size line under Working image still shows the greyed-out values.

Background detection

Active on/off · Mode Auto / Manual · Tolerance 0 – 150

What it does

Background detection removes the background of your image before the colors are reduced. The removed pixels become transparent. They reach the embroidery step as white and are normally left out there, so they are not embroidered; see Background detection and the Embroidery parameters. This has two more advantages:

• The background no longer uses up one of the colors of Target number of colors.
• For a clean logo, the original logo colors can be kept exactly. See How to count the colors of a logo.

The removal is visible in the preview under Server result after Optimize; removed areas show the preview background. The Working image shows your image without the removal. The supplied default preset switches Background detection on (Auto, Tolerance 30).

When you need it

Use it for a logo or graphic on a plain background, for example black text on white. Untick Active for photos without a real background.

The controls

Watch out

• Pipette on a background that is not white. The pipette also sets Assign background color to Specify and copies the picked color into Background color (R,G,B). These settings stay for the next images. Because removed areas reach the embroidery step as white, a non-white color there means the removed background can be stitched as a white fill. After using the pipette on a colored or off-white background, set Assign background color back to Automatic.
• Auto does nothing on an already transparent image. If less than a quarter of the image border is opaque (a PNG with a transparent background, or an SVG/AI without a background shape), Auto removes nothing. Manual always runs.
• Auto can remove motif parts. If the motif itself fills the image edges, Auto takes a motif color as the background and removes it wherever it touches the edge. Examples are a rectangular badge, a design running off the edges, or a motif after a tight crop. After Crop to image data, always check with Optimize. If motif parts are missing, pick the background with the pipette (Manual mode) or untick Active.
• Photos: Auto always finds some color, for example sky or a wall, and removes it where it is connected to the edge.
• Gaps in outlines: if an outline has a gap, the removal can leak through it and also remove the area inside.
• Rims. Blended edge pixels that differ from the background by more than the tolerance stay as a thin light or colored rim. A slightly higher tolerance removes more of the rim, but it can also remove light motif colors. For SVG and AI logos, Vector: no anti-aliasing (hard edges) (gear button ⚙ → Color reduction tab) reduces the rim (see Vector: no anti-aliasing). Soft shadows and feathered edges always become hard edges, with or without Background detection.
• Dark edges with Pre-smoothing. Together with Pre-smoothing from about 4, the colors along the edge of a photo-like motif can become darker. See Pre-smoothing.
• If everything is removed (for example with a very high tolerance and Remove color everywhere), Optimize reports "PNG enthaelt nur transparente Pixel" (the image contains only transparent pixels). Create embroidery data shows no error: it embroiders your original image unchanged, with its background, without color reduction and at its original size. Lower the Tolerance or untick Remove color everywhere.
• Crop to image data uses the Tolerance too, to tell margin from motif on images with an opaque border. On images with a transparent border it goes by the transparency. With Active ticked, whatever Background detection would remove also counts as margin. In Manual mode that is the Source color.
• Skip color reduction: the section is greyed out, and no background is removed when the embroidery is created. Crop to image data still uses the greyed-out Tolerance (and, if Active is ticked, Mode and Source). To change them, untick Skip, change the values, then tick Skip again.

Background detection and the Embroidery parameters

The Embroidery parameters contain two settings that sound similar to Background detection: Assign background color and Background fill. They work at a later stage and do not change the image. After the colors have been reduced, they decide which color areas are not stitched:

• Assign background color: Automatic uses the color that covers most of the image edge. Specify uses the color in Background color (R,G,B). The Pipette next to that field fills only this field and sets Specify; it does not change Background detection.
• Background fill = No leaves out every area in the background color, including enclosed areas. Yes leaves out only background areas that touch the image edge; enclosed areas in the background color are stitched.
• Areas removed by Background detection reach this stage as white, whatever color the original background had. With Automatic, white is then usually the background color. With Background fill = No, the white parts of your motif are therefore usually left out as well, such as white eyes or white text, including the white highlights made by Preserve white highlights (unless a thread table gives them a slightly darker white). If such white parts must be stitched, set Background fill to Yes.
• To have a background embroidered, unticking Active is not enough: with Automatic, a plain border color is still left out. Also set Assign background color to Specify with a color that does not occur in your design, and check the result with Create embroidery data.
• These settings also work when Skip color reduction is ticked.

Embroidery parameters

These settings control how the reduced image is turned into stitches. They take effect only when you click Create embroidery data; the Optimize preview does not use them. Skip color reduction does not switch them off.

• Checking a change: click Create embroidery data and look at the preview, Stitches and Cuts under Server result. Each Create uses license quota, so change related values together.
• Real millimeters. All sizes refer to the finished embroidery. If you change the size under Scaling, the same values can give a different result. For example, a stroke that is satin at 100 % can become a step fill at 200 %.
• Start values: the supplied default preset uses Line width 4, Satin stitch width 50 and Minimum line length 30. It is loaded again at every start; see Start values.
• Enter whole numbers. A decimal value such as 4.5 can make Optimize and Create fail.

How the stitch type is chosen

Each color area gets one stitch type. It depends on how wide the area is at its thickest point:

• An area is not split into thin and wide parts. One thick spot decides the whole area: a wide shape with a thin tail is stitched completely as fill.
• Wide areas are stitched first and narrow ones last, so small details lie on top. The Punch optimization options (gear button ⚙, on in the default preset) reorder only areas that do not overlap in the image, so small details still lie on top. Neighbors that only touch can swap along their border.
• Width is counted in whole image pixels and then converted to mm, in steps of 2 pixels. At 96 DPI (JPG and BMP files, and PNG files without a stored resolution) one pixel is about 0.26 mm, so even the thinnest line measures about 0.5 mm. With Line width 4 (0.4 mm) nothing becomes a running stitch; raise Line width to 6 or more to get running stitches from such an image.

Picture type

• Automatic preselection. Each time you open or crop an image, the client decides between Clipart and Scanned picture and shows "Auto-detected: …". This overwrites your earlier choice between the two, but keeps "highlight black". You can change the selection afterwards. Selecting a preset after opening sets the picture type stored in the preset; the "Auto-detected" note then no longer applies. If the preset is already selected, select — none — first and then the preset again (see Presets).
• Small effect after color reduction. Because the colors are already reduced, the picture type cannot add colors. Clipart and Scanned picture only remove specks and move single edge pixels; "highlight black" also widens dark shapes by one pixel.
• Pixel-based. The one-pixel widening is about 0.26 mm per side at 96 DPI and about 0.085 mm at 300 DPI.

Assign background color, Background color, Background fill

These settings decide which areas are not stitched because they are background:

• Assign background color has two options:
  • Automatic uses the color that covers most of the outer image edge: more than 70 % of it, or more than half and twice as much as the next color. If no color is dominant, nothing is left out and the background is stitched as well. If a design color fills most of the edge, for example a rectangular badge, that color is taken as the background and left out; then choose Specify with a color that does not occur in your design.
  • Specify always uses the color in Background color (R,G,B). The color of an area must match almost exactly to count as background: R, G and B may each differ by only about 5. For example, 250, 250, 250 counts as white, but 248, 248, 248 does not. The Pipette next to the field sets Specify automatically; typing values does not.
• Pipette and Background detection. The pipette reads your original image. With Background detection on (as in the default preset), the removed background arrives here as white. Picking a colored or off-white background then makes the removed area be stitched as a white fill. With Background detection on, keep Automatic or specify white (255, 255, 255). Use Specify and this pipette only when Background detection is off.
• Background fill
  • No leaves out every area in the background color, including enclosed ones such as white eyes on a white background.
  • Yes leaves out only background areas that touch the image edge; enclosed areas in the background color are stitched.
  • Despite the label, Yes does not embroider the background around your motif. To embroider the background, see Background detection and the Embroidery parameters.

Line width, Satin stitch width, Overlap and minimum sizes

Satin split, stitch lengths and density

Underlay, pull compensation and similar stitch settings are fixed and cannot be changed here. Options for color changes, thread trims and jumps are under the gear button ⚙ → Punch optimization; see Punch optimization.

Punch optimization

These three options are in the Settings dialog (gear button ⚙ → Punch optimization). "Punching" is the embroidery term for creating the stitch data. The options change the order in which the areas are stitched and which thread trims are made. In some designs the stitch direction of fill areas can also change (see below). The areas, colors and stitch types stay the same.

• They take effect only with Create embroidery data, not with Optimize. Skip color reduction does not affect them. They are ignored when an SVG/AI file cannot be converted and is created directly from its vectors (see For API users).
• The supplied default preset switches all three on, with Always cut above 30 mm and Max. visible bridge 2 mm.
• Checking the effect: after Create, Cuts under Server result shows the number of thread trims.
  • The number of color changes is not shown there. Number of thread colors counts the needles used and does not change with these options.
  • To see the color changes, open the saved design in your embroidery software or on the machine.
  • Each Create uses license quota, so compare only the combinations you need.

Minimize color changes (merge same colors)

Areas with the same thread color are stitched one after another, so each color is sewn in fewer blocks. This means fewer color changes and a shorter production time.

• Despite the label, no colors are merged: the same thread colors are used. Only the order changes.
• What lies on top stays on top. Areas that overlap or lie inside each other in the image keep their order.
• Areas that only touch along a border can change position. In the narrow strip where Overlap makes such neighbors overlap, the area stitched later lies on top. After reordering, this can be the other one. This is a very small change.
• In some designs, fill areas get a different stitch direction than with this option and Minimize jumps both off. This happens after one of two events among the wide areas: a fill area with more than three holes cannot be filled evenly and is filled in sections instead, or a fill area is left out because Minimum area size is set well above the default. Every fill area stitched after it in the original order (the same width or narrower) is then turned by 15° or a multiple of 15°. Satin areas and running stitches are not affected.
• The number of trims can go up or down, because two areas of the same color can be far apart.
• Designs with very many areas take a little longer to create.

Minimize jumps (optimize order)

Within each color, the areas are stitched in a sequence that keeps the jumps between them short. After each area, the software picks the closest remaining area of that color, measured between the centers of the areas. Shorter jumps mean less jump thread and often fewer trims.

• This option always groups the colors as well, exactly like Minimize color changes. While it is on, the Minimize color changes box has no effect: the result is the same whether the box is on or off.
• Otherwise it works like Minimize color changes: areas that overlap or lie inside each other keep their order, even if that makes a jump longer; areas that only touch can swap; and in some designs, fill areas get a different stitch direction than with both options off.
• To get the original stitch order and stitch directions, switch both options off. The original order stitches wide areas first, then narrow areas and lines.

Save thread trims (multilayer: don't cut overstitched jumps)

Between two areas of the same color that are stitched one after the other, the machine normally trims the thread when the jump is long. With this option the trim is left out if two conditions are met:

• the jump thread stays hidden, apart from at most the Max. visible bridge length;
• the jump is shorter than Always cut above.

The thread then runs on to the next area. The tie-off stitches at the end of the area and the tie-in stitches at the start of the next one are still sewn, so the thread cannot come loose. Fewer trims mean shorter production time and fewer thread ends. "Overstitched" in the label means that the jump thread is covered by stitching that follows later.

• A jump counts as hidden where it lies under a satin or fill area that is stitched later, in any color, or over a satin or fill area of the same color.
• It counts as visible over bare fabric (including holes inside areas), over areas of another color that were stitched earlier (the thread lies on top of them), and over running-stitch lines, which cannot cover a thread.
• A trim at a color change is never left out.
• Only jumps that are long enough to get a trim can save one. Shorter jumps never get a trim. The trim length is a server setting, 12.7 mm unless it was changed. With Always cut above 30 mm, only jumps between the trim length and 30 mm can save a trim. Always cut above must therefore be clearly higher than the trim length, otherwise the option has no effect.
• The option saves more when Minimize color changes or Minimize jumps is on, because more areas of the same color then follow each other. With Minimize jumps, the jumps between them are also shorter.

Watch out

• "Hidden" is decided by the shape of the areas, not by how densely they are stitched. On fills with low density (a high Stitch density value) or with strongly contrasting colors, for example a dark thread under a white fill, a covered jump thread can show through. In such designs lower Always cut above, so that fewer long threads run under the fill, or switch the option off. Max. visible bridge does not help here: it only counts thread that lies on top.
• Enter whole millimeters. Unlike the Embroidery parameters, which use 0.1 mm, these two values are in mm. A decimal value can make Optimize and Create fail.
• The two values are used only while the option is on.

Settings: Color reduction tab

The Settings dialog (gear button ⚙ → Color reduction tab) has two more color reduction options.

• Both take effect with Optimize and Create embroidery data; Vector: no anti-aliasing also with Crop to image data. After changing one, click Optimize or Create again.
• With Skip color reduction ticked, neither option has an effect, even though they are not greyed out.
• They stay on. They are not part of the supplied default preset, so they keep their last setting when the page is reloaded. Presets you save yourself do store them: selecting such a preset sets them to its values, and a default preset of your own does this at every start. Untick them when you no longer need them. If a result has one color fewer than expected, or an SVG looks flattened, check this tab first.

Preserve white highlights (e.g. eyes)

Without this option, small white details such as eye glints or light reflections can be merged into a neighboring color and disappear. With it, very light pixels get their own white color.

• When to use it: when small white details turn grey or disappear in the Optimize preview. To have them embroidered, also set Background fill to Yes; see the box below.
• Leave it off for photos, JPEG files and scans with glare or noise, for single-color embroidery, and when white areas should simply show the fabric.

What exactly happens

• Which pixels: every pixel whose R, G and B are all 240 or higher becomes white. This includes large white areas, very light grey and very pale cream tints, and a white background that was not removed, not only small details.
• When it acts: only if the image has at least 8 such pixels after Background detection. Otherwise nothing changes.
• Which white: if the reduced colors already include white, that color is used: with a Thread table the thread closest to white (for example the light grey 1003 with Madeira-CLASSIC), otherwise pure white or a very light color (R, G and B 240 or higher). If not, this white is added.
• White takes a target color only if it is missing. The image is first reduced to Target number of colors. If the result already contains white, the very light pixels use it and you keep all target colors. Only if white is missing are the other colors reduced to Target number of colors minus 1, and white is added.
  • For a logo with white or very light parts, count white as one of the logo colors; see How to count the colors of a logo.
  • Examples with a transparent or removed background: Target 1 gives 2 colors, the average color plus white. Target 2 on a black-and-white logo gives black and white.
• Specks stay. The white is set after Noise/dithering, so single light pixels remain as white specks, for example JPEG noise or glare in a photo. Pre-smoothing does not remove them either, because the test uses the original colors.
• With Background detection and Remove color everywhere on a white background, enclosed white details are already removed before this option acts. It cannot bring them back.

Vector: no anti-aliasing (hard edges)

When an SVG or AI file is converted to an image, its edges normally get blended in-between colors (the edge between red and white gets pinkish pixels). These extra shades can use up colors, prevent the original logo colors from being kept exactly, and leave a thin rim when a background is removed. The option works on SVG and AI files; it has no effect on PNG, JPG or BMP.

• AI files are drawn directly without anti-aliasing: edges get no blended pixels, and gradients inside the file stay as they are. Embedded pictures are drawn without smoothing.
• SVG files are drawn normally, and then every pixel is set to the nearest main color of the logo; semi-transparent edge pixels become either fully transparent or fully opaque. The points below about main colors, photos and gradients apply to SVG files.
• Use it for flat SVG and AI logos with solid colors, especially if they have an opaque background shape that Background detection removes. For SVG files, a thin rim in another logo color is still possible, but less likely.
• Main colors (SVG): a color counts as a main color only if it covers at least about 0.2 % of the motif, including an opaque background shape. That is 5 times more than the usual limit (see Very small color areas are merged). Example: on a motif of 50 × 50 mm, a detail smaller than about 5 mm² in its own color takes the nearest main color. Enlarging the design does not help. Together with Preserve white highlights, tiny white glints can be lost this way.
• SVG photos or gradients: not suitable. If the SVG also contains a flat color, for example a white frame, the picture is reduced to its main colors, in the worst case to that single color. A pure photo usually stays unchanged. Gradients may stay almost unchanged or be replaced by a few flat stripes. Leave the option off for such designs.
• No effect on SVG files that only contain a pixel picture with a transparency mask, which is typical of automatic image-to-SVG converters.
• Where to see it: the Working image does not show the effect until you use Crop to image data; the result under Server result after Optimize does. Every result has hard edges anyway, because color reduction gives each pixel one final color. The option mainly decides which color the edge pixels get before that step; for SVG files it also removes small details and gradient shades as described above.
• Tick it before cropping. Crop to image data converts the SVG or AI file into an image with the setting at that moment. Changing the option afterwards has no effect on the cropped image. To use it after cropping, open the file again, tick the option, and crop again.
• The hard edges have tiny stair steps of about 0.085 mm. They are too small to show in embroidery.

Settings: View tab

Preview background (Working image & Server result) sets the color shown behind the images in both preview areas. The default is a dark grey (#12151A).

• Display only. The color changes only what you see in the browser. It does not change the image, the color reduction, the embroidery or any saved file.
• Transparent areas show this color, for example a background removed by Background detection. The color does not appear in the embroidery: areas that are left out show the real fabric.
• Tips:
  • Choose the color of your fabric to judge how the design will look on it.
  • A light background makes dark details and dark rims visible. A dark background makes white highlights and light rims visible.
  • Switch between a light and a dark color to check a removed background for leftover rims.
• The change takes effect immediately. Reset restores the default.
• The color is stored in this browser only. It is not part of presets or of the supplied default preset, so selecting a preset does not change it.

Presets

A preset is a named set of settings. With presets you can switch between settings for different kinds of designs in one step, for example one for flat logos and one for photos. The Presets panel is in the right-hand column, below the Embroidery parameters.

What a preset contains

• Stored: all settings in the Color reduction panel except Scaling, including Skip color reduction, the Thread table and Background detection; all Embroidery parameters; and the Settings (⚙) tabs Punch optimization and Color reduction.
• Not stored: the size under Scaling, the server address (Server tab), the license key, the preview background (View tab) and the open file.
• Colors picked with a pipette are stored too. The pipette under Background detection writes the color into Source, switches Mode to Manual and ticks Active. Both pipettes set Background color (R,G,B) and switch Assign background color to Specify. A preset saved after picking then uses that fixed color as the background for every image. For a preset you want to use with many images, set Mode to Auto (or untick Active if the background should stay) and Assign background color to Automatic before saving.
• Picture type: opening or cropping a file sets Picture type to Clipart or Scanned picture automatically (see Picture type). To use the picture type stored in a preset, select the preset after opening the file. If the preset is already selected, for example the default preset after the start, select — none — first and then the preset again.
• Opening an SVG or AI file unticks Skip color reduction, even if the preset has it on. It stays unticked when you open a PNG file afterwards; tick it again or select the preset again. A preset saved while an SVG or AI file is open stores it as off.

Using the panel

The five buttons below Name show only an icon. From left to right they are Save, Rename, Delete, Export and Import. Point at a button to see its name.

• Changes are not saved into the preset automatically. After you change a value, the list still shows the preset's name, with no sign that the settings now differ. To keep the change, click Save with the same name. For the default preset, untick Default (load at start, read-only) first, click Save and then tick it again.
• To go back to the stored values, select — none — and then the preset again. Selecting the entry that is already selected does nothing.
• Selecting a preset does not update the Server result. Click Optimize or Create embroidery data again.

The default preset

At every start, the client selects the preset marked ★ and applies its settings. This replaces the values from your last session.

• Only one preset can be the default. Ticking Default (load at start, read-only) for another preset moves the mark. Unticking it leaves no default; the client then starts with the values from your last session.
• Ticking only sets the mark. It does not store the current settings in the preset. Save first, then tick.
• Read-only means that the default preset cannot be overwritten with Save, renamed or deleted. Untick Default first. You can still change the settings after selecting it and save them under a new name. Import can replace it; see Export and import.
• At start, the Name field shows the name of the default preset. To save a preset of your own, type a new name first; otherwise Save shows the read-only message.
• Settings that the default preset does not contain keep their last value. The supplied preset "Default" does not contain Skip color reduction, Background color (R,G,B) or the two options in the Settings Color reduction tab. A preset you save yourself contains all settings, so as your default it resets all of them at every start.

Where presets are stored

• Only in this browser. Presets are not stored on the server and are never sent with a request.
• Each browser, browser profile, Windows user and PC has its own list, and so does each address of the client: for example, http and https, or the server name and its IP address, count as different addresses. A new list starts with the supplied presets. A private window also starts with them and forgets all changes when it is closed.
• Clearing the browser's site data (cookies and other site data) deletes all presets.
• Use Export to keep a backup, and Export and Import to move presets to another browser or PC.
• If the client is open in two tabs, the tab that saves last overwrites the changes made in the other one. Edit presets in one tab only.

Export and import

• Export downloads all presets, including the default mark, as the file ace-presets.json. Changes on screen that you have not saved as a preset are not included.
• Import reads such a file, or a default.json file:
  • A preset with a new name is added at the end of the list.
  • A preset with the same name as an existing one (upper and lower case do not matter) replaces its settings and its default mark, without asking. This also applies to the read-only default preset.
  • Presets that are not in the file keep their settings; nothing is deleted. Only their default mark can be removed (see below).
• Only one default remains. If more than one preset is marked as default after the import, the one higher up in the list keeps the mark. A preset with a new name is added at the end, so it does not take the mark from your default. A preset that replaces one with the same name keeps its place. "Default" is usually at the top, so importing a default.json file makes "Default" the default preset again, even if you had chosen another one. Check the ★ after importing.
• Importing does not apply any settings. Select a preset afterwards. If the selected preset has just been replaced, select — none — first and then the preset again.
• Import only files that were exported by the ACE client. The values in the file are not checked, so an edited file can contain values that make Optimize or Create fail.

Supplied presets (default.json)

The presets a new list starts with come from the file default.json next to ACEClientWeb.html on the server. The supplied file contains one preset, "Default", marked as default: Target number of colors 12, Noise/dithering 5, Pre-smoothing 5, no thread table, Background detection on (Auto, Tolerance 30), Line width 4, Satin stitch width 50, Minimum line length 30, and all three Punch optimization options on.

• The client loads this file only when the browser's preset list is empty: at the first start, after the site data was cleared, and at the next start after all presets were deleted.
• A new default.json on the server does not reach browsers that already have presets. To get it there, save the new default.json on your PC (your administrator can give it to you) and import it with Import. This replaces the settings of "Default" and makes it the default preset again. If you use a default preset of your own, tick Default (load at start, read-only) for it again afterwards.
• Alternatively, untick Default, delete all presets and reload the page; the client then loads the current default.json. Export your own presets first. Importing that backup afterwards also brings back the old "Default".
• If default.json cannot be loaded, for example when it is missing on the server or the page is opened directly from disk, no message appears. The list then stays empty. The client starts with the values from your last session, or in a new browser with its built-in values: Target number of colors 8, Noise/dithering 2, Pre-smoothing 0, Background detection off, Line width 10, Satin stitch width 70, Minimum line length 50.
• Save current settings as default.json downloads the settings currently on screen as a preset named "Default", marked as default. It contains the same settings as a preset you save yourself, including Skip color reduction, Background color (R,G,B) and the Punch optimization and Color reduction tabs of the Settings dialog. The server address and the preview background are not included. It does not change the presets in this browser. To make it the supplied preset, replace default.json next to ACEClientWeb.html on the server. Keep a copy: the file is part of the installation, so an update can replace it.

Pre-smoothing or Noise/dithering?

Both settings make the result calmer, but they work at different points and fix different problems. They are often used together.

Quick start: recommended starting points

• The default preset is tuned for photos. For clean logos, set the number of logo colors and lower Noise/dithering to 2. If Preserve white highlights is on, count white parts as one of the logo colors.
• Some SVG and AI files are not real vector drawings: they only contain an embedded photo. Treat them like a noisy photo. The ACE client does not detect this automatically.

Start with these values, check the preview with Optimize, and then adjust one setting at a time:

For API users