Image preparation techniques

Before converting artwork to vector graphics, you frequently need to clean it up. To work effectively, the Convert function requires solid color images as input. You can improve artwork with the bitmap editing tools.

Note: For a full description of the editing tools in CorelDRAW Graphics, refer to the electronic User Guide available via the MS Windows® Start > Programs group. Alternatively, use the online help available from the Help menu.

Outlined vs non-outlined images

Before preparing your image you need to know what type you are using. For the purposes of automatic digitizing, there are two categories – outlined and non-outlined. Outlined images ideally have a solid black outline around each colored area. Non-outlined images ideally consist of solid areas of color. Outlined and non-outlined images require different methods of preparation.

Image cleanup

In practice, cleaning up scanned images may involve any one or a combination of the following techniques:

Color reduction

Sometimes an image looks clean but extra colors have been introduced during scanning or processing. Color reduction means reducing the actual number of image colors in order to eliminate unnecessary detail and reduce each block to a single color. Color reduction also cleans the image, removing any noise and anti-aliasing present. This in turn helps minimize the number of trims and color changes required in the resulting embroidery design. Color reduction should only be applied if the loss of detail does not affect the image shapes. Before reduction, the colored areas in the image below include many colors. After reduction, each area is reduced to a single color. The detail is preserved.

Be aware that some techniques are better for removing noise and anti-aliasing but not so good for processing dithering in non-outlined images. See also Choosing suitable artwork.

Outline sharpening

Outline sharpening means emphasizing outlines bordering distinct color blocks. These may have been indistinct in the original or made so by the scanning process. Outline sharpening is important for vectorizing because it makes it easier for EmbroideryStudio to identify areas for conversion to embroidery.

Noise filtering

Noise filtering means restoring the solid color blocks of the original artwork in scanned images. This is achieved by merging different shades into one solid color. Noise filtering is important for vectorization because it makes it easier for EmbroideryStudio to identify solid color blocks to become embroidery objects in the resulting design. It also cleans up blurred or mottled areas of color.

Image preparation summary

Action	Outlined image	Non-outlined image	Photograph
Scan artwork	Scan in RGB mode Use sharpening	Scan in RGB mode No sharpening	Scan in RGB mode
Scan line drawing	Scan in two color mode	-	-
Touch up graphics	Crop Add or edit outlines Edit colors Remove noise	Crop Edit image shapes Edit colors Remove noise	Crop Convert to grayscale Remove background Adjust contrast
Adjust bitmap	Adjust outline contrast manually.	Adjust outline contrast manually.	Adjust outline contrast manually.
Prepare bitmaps	Adjust outline contrast manually. Automatically: blend each outlined block into a single color remove anti-aliasing, noise and dithering sharpen outlines.	Reduce colors to a specified number. Automatically: reduce each block to a single color remove anti-aliasing, noise and dithering remove colors less than specified area.	-
Vectorize bitmaps	CorelDRAW Graphics provides the latest CorelDRAW® drawing tools. These offer many sophisticated techniques for drafting outlines and shapes on screen. Refer to the electronic User Guide available via the Windows Start > Programs group. Alternatively, use the online help available from the Help menu.
Convert vectors directly	EmbroideryStudio provides techniques for both converting vectors directly to embroidery as well as manual digitizing of prepared artwork. See Digitizing Shapes for details.
Digitize automatically	Manual Auto-Digitizing Instant Smart Design Smart Design	Manual Auto-Digitizing Instant Smart Design Smart Design	Photo Flash Color PhotoStitch