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Chapter 2: When it's All about Image |  |
The chapter begins with 'Fundamentals' related to all work with images then develops skills in a 'Task' based fashion using the examples illustrated below.
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| This
chapter covers various aspects of Image editing for CNC purposes.
Images are often a starting point for creation of vectors or
meshes. Applied correctly they can greatly reduce the need
for manual editing when generating content for 2D or 3D CNC
applications. The chapter begins with 'Fundamentals' related to all work with images then develops skills in a 'Task' based fashion using the examples illustrated below. |
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| Task 01: This
task is an introduction to basic image editingwith GIMP a well
respected and fully featured FREE application.
The aim of this task is to create optimised lineart. Principles applied in this example are not difficult to follow and are easily exploited in other work using similar source material. Results can be used to generate vectors or as the basis for height-mapping. |
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| Task 02: Examination
of image simplification using built in GIMP
'filters'.
When source images are shaded or toned it's often necessary
to reduce image complexity before use as a source image for
vectorisation or mesh generation.
The task employs a shaded drawing but techniques described in this example can just as easily be applied to photographic source material. |
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| Task 03: Use
of GIMP's 'Path' tool to repair images based on 'stroking' the 'path'
with brushes.
Use of the 'Tapered Stroke on Path' script addon to sympathetically adjust and edit image content. |
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| Task 04: Re-scaling
lineart. GIMP selection tools and options allow vector based scaling.
This avoids generation of 'jaggies' or similar artefacts and helps
maintain high quality in source images.
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| Task 05: Examination of principles of height-mapping, using a basic example. The resulting image is applied in Chapter 6 to generate a 3D mesh. Demonstration of the GIMP path tool applied to create shaped text. Results from this task are suitable for use in ANY displacement software. They are also suitable for use in ANY toolpath generation software. |
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| Task 06: Demonstration of 'simple' height-mapping based on a found image from the internet. Even though this image appears to be more complex it exploits the same principles as the previous task. Adaption to automatically generate suitable shading using built in GIMP features is the only real difference. Results are suitable for use in ANY displacement or path generation software. |
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| Task 07: A
slightly more complex example considers content differentiation, use of
texture and patterns, height-tracking detail and shaping with blur.
This task is based on a source image that might be more commonly associated with generation of 'Dimensional Clipart'. Much of the content on the site 'Downloads' page is created using these methods. Results are suitable for use in ANY displacement or path generation software. |
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| Task 08: Demonstration
of the use of GIMP 'Apply Modes' in the height-mapping process.
This can greatly simplify the whole process allowing a very
basic shaped gradient to benefit from algorithmic adjustment
of colour values. Results
are suitable for use in ANY displacement or path generation
software.
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| Task 09: Techniques to provide optimum results when gmax is used as the displacement 'engine' when generating meshes. As is clear from this image, results can equate to the output of very costly software. There is no real difference to work in GIMP to generate this type of result. This example demonstrates use of 'Gradients along Paths' to algorithmically generate different levels where areas pass 'behind' content in an image. |
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| Task 10: Application of height-mapping techniques to generate 'Dimensional Text'. Simple colour curve adjustments can create a wide range of shaped text. Coupled with 'Text along Path' methods from Task 05, these methods provide an almost infinite range of possibilites for use of text. Results A to C are suitable for use in ANY displacement or path generation software. The result in view D requires use of gmax specific displacement options. |
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| Task 11: Image editing techniques to generate both a vector and a corresponding heightmap to generate Intaglio' or 'V-Carving' toolpaths for text and graphic content. gmax and CNC_Toolkit are required to create gCode based on a displaced vector. This example is applied in Chapter 7. |
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