Import Images the Right Way (Size Does Matter!)
Posted: Wed Nov 01, 2006 10:10 am
This article explains how to successfully import bitmap based images (e.g. BMP, GIF, PNG) into FontCreator. If you are looking for tips about importing vector based images, then read this tutorial:
From Vector (e.g. an Adobe Illustrator image) to Font
Each month we receive numerous questions about how to improve the quality of imported glyphs. Some people ask how to reduce the number of points that make up a contour, while others want more detail. In both situations it is far better to prevent the problem than try to fix it. In this tutorial you'll find some general tips and tricks, related to the source image and the settings used during the conversion from image to outlines, that should lead to better import results.
Last week a customer (who gave me permission to use the image) send me this image and asked how to improve the quality of the generated contours. The letter "a" is hand-drawn at the size of 1 inch and is scanned at 150 dpi.
Image Dimension
Although the user manual tells you the recommended image dimension for importing images is between 100x100 and 500x500 pixels, this image (154x137) is just too small, because the character is actually a group of tiny strokes. So this detailed image should have been larger. Because this isn't always that obvious, it is best to experiment with smaller and larger images (for example scan at 150, 300, 600 and 1200 dpi). When you don't have the original hand-drawn letter, you can also resize your images with a paint utility (e.g. Microsoft Paint, Corel Paint Shop Pro or Adobe PhotoShop). This is not recommend as the results are usually slighty better when you use an originally scanned image.
Here is the same letter but scanned at 600 dpi (609x555):
Import Image dialog settings on the Image tab
Almost all default settings are fine:
Negative: Not checked
Threshold: 63
Erode - Dilate: No filter
Smooth Filter: Smooth
Import mode: Trace
Import Image dialog settings on the Glyph tab
Bounding: Contours
Position: Left Bottom (x = 0, y = 0)
Size Multiplier: depends on image size
I've used the size multiplier to compensate for the different scan resolutions.
The Results
The results are shown here (screenshots taken from Glyph edit windows with 18% zoom factor):
Personally I prefer the result from the 600 dpi scanned image. If you are satisfied with the result of the 300 dpi scan, do use that as it has fewer points. The 1200 dpi image generates way to much points, so that one is over the edge.
Resize the Glyph
It is almost always necessary to resize the glyph's outlines after importing an image. As explained in the user manual, there are several ways to accomplish this. When you know the desired height of a glyph, you could select all contours (in contour mode press CTRL-A) and then use the Size tab on the Transformation toolbar to resize to a fixed height. Just be sure you use the "Lock aspect ratio", as shown here:
Adjust Bearings
The left and right side bearings can be changed by dragging the vertical dashed lines to their desired position. The contours should be positioned between these lines, otherwise characters will overlap each other. You can also use the Bearings tab on the Transformation toolbar.
Conclusion
The bottom line is, do experiment with different scan resolutions before you decide to digitize your whole handwriting.
Do let me know if you would also like to see a more common hand-drawn letter and I'll show results of that as well.
From Vector (e.g. an Adobe Illustrator image) to Font
Each month we receive numerous questions about how to improve the quality of imported glyphs. Some people ask how to reduce the number of points that make up a contour, while others want more detail. In both situations it is far better to prevent the problem than try to fix it. In this tutorial you'll find some general tips and tricks, related to the source image and the settings used during the conversion from image to outlines, that should lead to better import results.
Last week a customer (who gave me permission to use the image) send me this image and asked how to improve the quality of the generated contours. The letter "a" is hand-drawn at the size of 1 inch and is scanned at 150 dpi.
Image Dimension
Although the user manual tells you the recommended image dimension for importing images is between 100x100 and 500x500 pixels, this image (154x137) is just too small, because the character is actually a group of tiny strokes. So this detailed image should have been larger. Because this isn't always that obvious, it is best to experiment with smaller and larger images (for example scan at 150, 300, 600 and 1200 dpi). When you don't have the original hand-drawn letter, you can also resize your images with a paint utility (e.g. Microsoft Paint, Corel Paint Shop Pro or Adobe PhotoShop). This is not recommend as the results are usually slighty better when you use an originally scanned image.
Here is the same letter but scanned at 600 dpi (609x555):
Import Image dialog settings on the Image tab
Almost all default settings are fine:
Negative: Not checked
Threshold: 63
Erode - Dilate: No filter
Smooth Filter: Smooth
Import mode: Trace
Import Image dialog settings on the Glyph tab
Bounding: Contours
Position: Left Bottom (x = 0, y = 0)
Size Multiplier: depends on image size
I've used the size multiplier to compensate for the different scan resolutions.
The Results
The results are shown here (screenshots taken from Glyph edit windows with 18% zoom factor):
Personally I prefer the result from the 600 dpi scanned image. If you are satisfied with the result of the 300 dpi scan, do use that as it has fewer points. The 1200 dpi image generates way to much points, so that one is over the edge.
Resize the Glyph
It is almost always necessary to resize the glyph's outlines after importing an image. As explained in the user manual, there are several ways to accomplish this. When you know the desired height of a glyph, you could select all contours (in contour mode press CTRL-A) and then use the Size tab on the Transformation toolbar to resize to a fixed height. Just be sure you use the "Lock aspect ratio", as shown here:
Adjust Bearings
The left and right side bearings can be changed by dragging the vertical dashed lines to their desired position. The contours should be positioned between these lines, otherwise characters will overlap each other. You can also use the Bearings tab on the Transformation toolbar.
Conclusion
The bottom line is, do experiment with different scan resolutions before you decide to digitize your whole handwriting.
Do let me know if you would also like to see a more common hand-drawn letter and I'll show results of that as well.