pcb-rnd knowledge pool

 

Background Image: displaying a background image while editing a layout

background_image_old by Erich Heinzle VK5HSE on 2017-01-05

Tags: howto, gui, layout, background, image, reverse engineer, duplicate, menufile

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Abstract: Duplication of an existing design from a photograph of a PCB, or from an image scanned from a book, or from a screenshot from an electronic publication, is made easier by being able to display the image in the background of the layout being edited. The image stretches to fit the height and width of the current layout.

  Users keen to duplicate an existing PCB for which no gerber or design files exist can duplicate the layout in pcb-rnd easily by displaying a picture of the features to be duplicated in the background of the layout being edited.

The image does not become part of the PCB design, it is merely displayed as a background image during layout of the design.

The image is loaded at the time pcb-rnd is launched with the following command line flags:

pcb-rnd --bg-image ~/path/to/picture/cropped-pcb-artwork-for-circuit-board.png

Most common image formats are supported.

Here is an example of PCB artwork in the background of the layout:

The image is stretched to fit the board size. The user needs to modify the layout size (height and width) in the preferences dialog to match the size of the PCB being duplicated.

If the dimensions of the board are not precisely known, the measurement tool invoked with the key sequence {a m} while the cursor is over the feature of interest, allows the distance from one feature to another to be determined. This allows scaling in the horizontal and vertical direction to be calculated, by measuring the displayed size of features of known dimensions, i.e. a DIP8 footprint's pad spacing, allowing the board size to be adjusted accordingly.