Tutorial 1 - Halftone Bitmap to SVG

Tutorial 1 - Halftone Bitmap to SVG - Using Gimp & Inkscape

In this tutorial we will load the original photo bitmap into Gimp, change the contrast a little and apply a halftone filter. Then trace and convert the bitmap to SVG using Inkscape.

Project Photo - Gimp

If you wish to use the Project Photo below: 
Click, Right Click, Copy and Paste into Gimp:

Project Photo

Levels - fig 1

Menu - Colours, and select Levels. We are going to adjust the input levels slightly 

See the 3 red circles in fig 1: 

Alter left value to 0

Alter middle value to 0.47

Alter right value to 2.31

Click OK

You can also adjust the levels by using the little arrows

fig 1

Layers - fig 2

Mode: Soft light - Click arrow (circled) and select from drop down menu

Duplicate Layer - Right click existing layer (circled) and select 

fig 2

Newsprint - fig 3

Now we are going to create a halftone pattern to the image:

Menu - Filters - Distorts, and select Newsprint 

For this project all we are going to change is the RGB Angle values:

Red Angle: 15.0

Green Angle: 15.0

Blue Angle: 15.0

And Oversample slider to 15

Click OK

fig 3

(You may wish to Merge layers, Save or Export the image now, but I am not going through those steps here)

Menu - Edit - Copy Visible

Gimp End

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Now we switch to Inkscape: 

Menu - Edit - Paste the Halftone bitmap we just created

Halftone Bitmap

Trace Bitmap - fig 4

Convert the image to SVG by auto tracing

Menu - Path - Trace Bitmap

Scans: 6

Colors: Click Radio button

Smooth: Uncheck

Remove background: Check

Options Click

Takes you to Options page in Trace Bitmap

fig 4

Options - fig 5

Suppress Speckles check, Size: 5

Update

OK

fig 5

Document properties - fig 6 and fig 7

The Svg now lies on top of the bitmap, click and drag the image a little to separate, then click and remove the bitmap.

To set the desired printing area:

Select the Svg image as in fig 6

File Menu - Document properties 

Click the + Resize to page content... expander

fig 6

Then click Resize page to drawing or selection as in fig 7

Maybe alter the border preferences

fig 7

Save the SVG