Draw Guide 7.1

Chapter 6,
Editing Images

Raster Graphics


This document is Copyright © 2021 by the LibreOffice Documentation Team. Contributors are listed below. This document maybe distributed and/or modified under the terms of either the GNU General Public License (, version 3 or later, or the Creative Commons Attribution License (, version 4.0 or later.

All trademarks within this guide belong to their legitimate owners.


To this edition

Peter Schofield

Elzett Kotze

Jean Hollis Weber

To previous editions

John Cleland

Martin Fox

Jean Hollis Weber

John A Smith

Peter Schofield

Regina Henschel

Claire Wood




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Publication date and software version

Published July 2021. Based on LibreOffice 7.1 Community. Other versions of LibreOffice may differ in appearance and functionality.

Using LibreOffice on macOS

Some keystrokes and menu items are different on macOS from those used in Windows and Linux. The table below gives some common substitutions for the instructions in this document. For a detailed list, see the application Help.

Windows or Linux

macOS equivalent


Tools > Options

LibreOffice > Preferences

Access setup options


Control+click or right-click depending on computer setup

Open a context menu

Ctrl (Control)


Used with other keys



Open the Styles deck in the Sidebar


Earlier chapters of this Draw Guide have dealt only with vector graphics. The most common types of vector graphics in use are as follows:

However, Draw also contains a number of functions for handling raster graphics (bitmaps) such as photographs and scanned pictures, including import, export, and conversion from one format to another.

Draw can read all the majority of graphic file formats. It has a subset of capabilities similar to raster graphics programs like Adobe Photoshop or Gimp. Raster graphics are generally images or pictures that use one of the following formats, which are the most common formats in use:

Importing images


To import image files into a drawing, go to Insert > Image on the Menu bar or click on Insert Image on the Standard toolbar to open the Insert Image dialog (Figure 1).

Draw contains import filters for the majority of graphic formats. If the file being imported has a graphic format not covered by the import filters, then it is recommended to use one of the many free graphic conversion programs to convert the file into a format that Draw recognizes.

If Preview is selected in the Insert Image dialog, a preview of the file is shown in the box on the right-hand side. This makes it easier to select the file required and also checks that Draw can import the file format used.

Figure 1: Insert Image dialog



Embedding a graphic into a drawing makes the image a permanent part of the drawing. Any changes made to an embedded graphic only appear in the drawing where the graphic was embedded. The original graphic file is not affected.

Embedding happens when a graphic is imported into a drawing using one of the following methods:

The main advantage of embedding graphics into a drawing is that the graphic is always available no matter what computer is used to open the drawing.

The main disadvantage of embedding graphics is that it creates large file sizes, which may not be desirable if there is limited capacity for storing computer files. Also, if the original graphic is altered, then the embedded graphic is not updated each time the drawing is opened.


When a graphic is to be embedded into a LibreOffice drawing, make sure that the Insert as Link option is not selected in the Insert Image dialog.

Figure 2: Confirm Linked Graphic dialog



Linking to the original graphic does not insert the graphic into a drawing, but creates a link to where the original graphic file is located on the computer. Each time the drawing is opened, any linked graphics are displayed in the drawing.

The main advantage of linking a graphic file when placed in a drawing is that if the original graphic file is altered or replaced with a graphic using the same filename, the version of the graphic in the drawing is always up to date. The next time the drawing is opened, the latest version of the graphic is also opened in the drawing. Also the file size of the drawing is much smaller and the original graphic can easily be edited with specialized external applications.

The main disadvantage of linking graphics is that the link must be maintained between the drawing and the embedded graphic file for linking to work correctly. If the drawing or original graphic file is moved to another computer location, then any links must be updated to include the new location.

1)  Open the Insert Image dialog.

2)  Select the Insert as Link option in the Insert Image dialog.

3)  Select the required graphic file and click on Open to open the Confirm Linked Graphic dialog (Figure 2).

4)  Click on Keep Link to link the file and close the Confirm Linked Graphic dialog.

5)  If necessary, click on Embed Graphic to embed the file if it is not to be linked. This also closes the Confirm Linked Graphic dialog.


When a graphic file is linked to a LibreOffice drawing, the format of the linked graphic is not changed.

Editing links

Links can be updated, modified, or broken as follows:

1)  Go to Edit > Links to External File on the Menu bar to open the Edit Links dialog (Figure 3).

2)  Select the link to be edited.

Figure 3: Edit Links dialog


3)  Click on Modify, Break Link, or Update as appropriate.

4)  Click on Close to save the changes to the link and close the Edit Links dialog.


With most scanners a scanned image can be inserted into a drawing or document. Scanned images are embedded using PNG format. Make sure the scanner is configured for the computer and supported by the SANE system for a Linux operating system, or TWAIN for a Windows or Mac operating system.

1)  Place a document, drawing, or photograph in the scanner and make sure that the scanner is switched on and ready.

2)  If this is the first time the scanner has been used with LibreOffice, go to Insert > Media > Scan > Select Source on the Menu bar to select the scanner. If the scanner has been used before, go to Insert > Image > Scan > Request on the Menu bar.

3)  The rest of the procedure depends on the scanner driver, interface, and computer operating system. Normally, scanning options need to be specified such as resolution, scan window, and so on. Consult the documentation that came with the scanner for more information.

4)  When the image has been scanned, Draw places it in the drawing. At this point it can be edited like any other graphic.


If more than one scanning device is connected to the computer, the device is selected when the source is selected. This selection becomes the default source when using scan requests until another device is used as the scanning source.

Copying and pasting

Copying and pasting a graphic into a drawing is another way of embedding graphics. The copied graphic can be an image already embedded in another document or drawing, or it can be a graphic file such as a drawing, document, or photograph.

After copying, select the format for pasting a graphic into Draw using Edit > Paste Special > Paste Special on the Menu bar to open the Paste Special dialog. Available formats for pasting depend on the type of image copied onto the clipboard.


When copying and pasting images into a drawing, please respect the copyright and license of the image being copied.

Dragging and dropping

Dragging and dropping is another method of embedding graphics into a drawing and can be used on graphics that have been embedded or linked. The way that dragging and dropping works is determined by the computer operating system. Behavior of dragging and dropping is normally controlled using the Ctrl or Ctrl+Shift keys in combination with the mouse.

Objects and images which are used frequently can be stored in the Draw Gallery. From the Gallery, a copy of the object or image can be simply dragged onto the drawing. Working with the Gallery is dealt with in Chapter 11, Advanced Draw Techniques.

Exporting graphics

Exporting files

By default Draw saves drawings in the *.ODG format. Some software programs cannot open *.ODG files. To make drawings available for other programs, the file can be exported in various formats. The export procedure used depends on the computer setup and computer operating system being used. The following procedure is an example export procedure.

1)  Open the ODG file being exported.

2)  Go to File > Export on the Menu bar and open the Export dialog. An example of an export dialog is shown in Figure 4.

3)  Enter a new filename for the exported file and navigate to the folder where the exported file is to be saved.

4)  Select the required file format from the options in the drop-down list.

5)  Click Export and the file is exported as a new file in the selected file format.

Figure 4: Example export dialog


6)  Depending on the file format selected, another dialog may open allowing options to be selected for the export format.

7)  Depending on the additional dialog that may open, click on Export, Create, or OK and the file is exported as a new file in its new format.

Exporting objects

Exporting individual objects, or a group of objects, from a drawing file is similar to “Exporting files” above. Open a drawing file and then select the object or objects for export. Make sure to choose the Selection option in the export dialog, as shown in Figure 4.

Using this method, an imported image can be modified, annotations added to it, and make other changes, then select it and export for use in another drawing or document.

Formatting images (raster objects)

Images (raster graphics) can be edited and formatted using one of the following methods to add or change filters and adjust the properties of color, lines, areas, and shadows:

Raster graphics included in a group behave like other objects when the properties of the group are edited and formatted.


Any formatting changes made to a graphic using the tools in LibreOffice only appear in the drawing where the graphic was modified. The original graphic file is not affected.

Naming images

Draw names objects, including inserted images, Shape 1, Shape 2, and so on, in the order of insertion into a drawing. It is recommended to rename objects, including images in a drawing, with a unique name Names make images and other objects easily identifiable in the LibreOffice Navigator.

1)  Select an image, then use one of the following methods to open the Name dialog, where a unique name can be entered for the selected image:

2)  Enter a name in the Name box and click OK.

Image toolbar

The Image toolbar (Figure 5) normally appears when an image or picture that is a raster graphic is selected. The Image toolbar can be fixed at the top of a drawing or as a floating toolbar. The default set of tools on the Image toolbar are as follows. For more information on the Image toolbar and the available tools, see Appendix B, Toolbars.

Figure 5: Image toolbar


Figure 6: Shadow and Image sections in Properties deck on Sidebar


Figure 7: Color toolbar


Cropping images

Cropping is a method of hiding unwanted areas of an image or changing the size of an image in a drawing. Changes made when cropping an image only change the display of the graphic in a drawing and not the original graphic file.

Quick cropping

After selecting a graphic, it can be cropped quickly using one of the following methods:

Selection handles appear around the selected image (Figure 8) and the image is cropped as follows:

Figure 8: Example image ready for cropping with selection handles


Crop dialog

For more control and accuracy over the cropping functions, it is recommended to use the Crop dialog (Figure 9). After selecting an image, go to Format > Image > Crop Dialog on the Menu bar to open the Crop dialog.

Figure 9: Crop dialog



In the Crop dialog, the Width and Height are treated as independent values. Changing one without the other can result in significant distortion of the image and this may not be what is required.

Exporting cropped graphics

If a cropped graphic is to be used in another drawing, use one of the following methods after selecting the cropped graphic:

Compressing images

If a large image is inserted into a drawing and resized to fit into the layout of the drawing, the complete full-size original image is stored in the drawing file. This preserves its content, possibly resulting in a large file to store or send by mail.

If some loss of image quality can be accepted, the image can be compressed reducing its data volume while preserving its display in the page layout;

1)  Open the Compress Image dialog (Figure 10) using one of the following methods:

Figure 10: Compress Image dialog


2)  Select the type of compression and the resolution required.

3)  Click on Calculate New Size to update the image information when the Compression and Resolution settings are changed.

4)  When satisfied with the new settings, click OK to apply the settings.

5)  If the resulting image is not acceptable, use the keyboard shortcut Ctrl+Z to undo the changes and select another compression setting.

Image filters

Draw offers eleven filter effects that work on a selected graphic and they can be combined. Filters always apply to the entire graphic and it is not possible to use filters to edit only a part of the graphic.

1)  Select a raster graphic to open the Image toolbar.

2)  Apply an image filter using one of the following methods:


If a graphic is embedded into a drawing, any image filters are applied directly to a selected graphic and the original graphic file is not changed. Save the drawing to retain any filter effects applied to the graphic in a drawing.

Figure 11: Image Filter toolbar and available filters



After a drawing is saved and closed, the effects of image filters become permanent. If image filter effects are not satisfactory, use Edit > Undo on the Menu bar to cancel the filter effects before saving the drawing.

The image filters available for application to a raster graphic are as follows:

Figure 12: Invert image filter


Selecting this filter opens the Smooth dialog (Figure 14) where the smooth radius parameter is set.

Figure 13: Smooth image filter


Figure 14: Smooth dialog


Figure 15: Sharpen image filter


Figure 16: Remove Noise image filter


Selecting Solarization opens the Solarization dialog (Figure 18), where the degree of solarization (Threshold value) can be specified. Entering a value above 70% reverses the inversion effect on colors. Selecting Invert reverses the effect of the Solarization image filter.

Figure 17: Solarization image filter


Figure 18: Solarization dialog


Selecting the Aging filter opens the Aging dialog (Figure 20), where the Aging degree can be defined and create an old look for the image.

Figure 19: Aging image filter


Figure 20: Aging dialog


Selecting Posterize opens the Posterize dialog (Figure 22), where the number of poster colors can be defined to produce the effect required.

Figure 21: Posterize image filter


Figure 22: Posterize dialog


Figure 23: Pop Art image filter


Figure 24: Charcoal Sketch image filter


Figure 25: Relief image filter


Figure 26: Emboss dialog


Selecting this image filter opens the Mosaic dialog (Figure 28), where the number of pixels for Width and Height of the tiles is set. Selecting Enhanced edges enhances the edges of each tile, creating a sharper definition.

Figure 27: Mosaic image filter


Figure 28: Mosaic dialog


Replacing colors

The Color Replacer tool only allows replacement or changing a color in an embedded graphic for another color or set a color as transparent. Up to four colors can be replaced at once. An area of the graphic cannot be selected for editing as this tool only works on the entire graphic.

The selection of replacement colors can only be from one of the available palettes in LibreOffice. New colors cannot be defined here, but custom colors can be created before using the Color Replacer tool. For more information on creating colors, see Chapter 11, Advanced Draw Techniques.


The Color Replacer can only be used on embedded graphics. If the Color Replacer is used on a linked graphic, the following error message appears “This image is linked to a document. Do you want to unlink the image in order to edit it?”. Click on Yes to unlink and embed the graphic.

Color Replacer dialog

Replacing colors

1)  Select an embedded image to start using the Color Replacer.

2)  Go to Tools > Color Replacer on the Menu bar to open the Color Replacer dialog (Figure 29).

3)  Click on Pipette at the top of the Color Replacer dialog to activate the color selection mode.

4)  Move the cursor over the color to be replaced in the selected image and a preview of the color appears in the box next to Pipette.

5)  Click on the color. The selected color appears in the first Source color preview box and a check mark appears next to it

6)  To select another color, place a check mark next to the second Source color preview box and click on another color in the selected image. A maximum of four colors can be selected in the Color Replacer dialog.

7)  Enter the amount of tolerance required for replacing each selected color in the Tolerance boxes. The default selection is 10% tolerance.

8)  In Replace with, select a color palette from the drop-down list, then select the required color from the color palette. Transparent is the default selection.

9)  After selecting up to four colors for replacement, click Replace to replace the colors in the selected graphic. An example of color replacement is shown in Figure 30.

10)  There is no preview of the effect. If the result is not satisfactory, select Edit > Undo > Color Replacer in the Menu bar and repeat the color replacement.

Figure 29: Color Replacer dialog


Figure 30: Example of using color replacer



Using the Color Replacer replaces all occurrences of the Source color that are in the selected image.


The default selection of Transparent in the Replace with boxes removes the selected color from the image and creates transparent areas in the selected image.

Replacing transparent areas

To replace any transparent areas in an image with a color use the following procedure:

1)  Go to Tools > Color Replacer on the Menu bar to open the Color Replacer dialog.

2)  Click on the image with transparent areas to select the image.

3)  Select Transparency in the Color Replacer dialog so that a check mark appears next to Transparency.

4)  Select a color palette from the drop-down list next to Transparency, then select a color from the selected palette.

5)  Click on Replace and the transparent areas are filled with the selected color.

6)  There is no preview of the effect. If the result is not what you required, select Edit > Undo > Color Replacer in the Menu bar.


Contour conversion

Contour conversion converts a selected object to a polygon, or a group of polygons, with four corner points. If an image was converted to a contour, then the converted image is set as a background graphic. If the conversion creates a group of polygons (for example, contour conversion of a text object), then enter the polygon group before selecting an individual polygon within the group. For more information on working with groups, see Chapter 5, Combining Multiple Objects.

After an object is converted to a contour, the object can no longer be edited normally. Instead, the contour converted object is edited using Edit > Points on the Menu bar to adjust its shape. For more information on editing points, see Chapter 3, Working with Objects.


Any editing to an object must be completed before carrying out a contour conversion because any further editing is not possible on the converted object.

1)  Carry out all necessary editing on the object before converting to a contour.

2)  Make sure the object is selected.

3)  Convert the object to a contour using one of the following methods:


No confirmation dialog is provided for a contour conversion.

Polygon conversion

Polygon conversion is used to convert a selected image into a group of polygons filled with color. The image is also converted to a vector graphic and can be resized with no loss of image quality or distortion of any text.

After conversion, the graphic can be broken into groups of polygons and then split into individual polygons. Breaking and splitting allows editing or deletion of individual colors within the graphic.

Conversion options and controls


1)  Select an image in a drawing.

Figure 31: Convert to Polygon dialog


2)  Convert the image into a polygon using one of the following methods and open the Convert to Polygon dialog (Figure 31):

3)  Select Number of colors and Point reduction to be used in the conversion.

4)  Select Fill holes to prevent any blank areas appearing in the converted image.

5)  Enter the number of pixels to use for Tile size.

6)  Click Preview to check how the converted graphic will look.

7)  Make any necessary changes to the settings and check the preview again.

8)  If the converted image meets the expected requirements, click OK to convert the image to a polygon and close the Convert to Polygon dialog.


No confirmation dialog is provided for a polygon conversion.


After converting an image to polygons, the vectorized image can be broken into groups of polygons. Each group of polygons consists of one color and becomes an object that can be used in another drawing.

1)  Convert an image to polygons, see “Converting” above.

2)  Make sure the converted image is selected, then use one of the following methods to break the image into groups of polygons:

3)  Click on a color in the image and drag the group of polygons filled with that color out of the image to create a new image.

4)  Alternatively, press Delete and delete the color from the image.


After converting an image to polygons and breaking the image into groups of polygons, these polygon groups can be split into individual polygons.

1)  Convert an image to polygons, see “Converting” above.

2)  Break the image into groups of polygons, see “Breaking” above.

3)  Select the image, then use one of the following methods to split the groups of polygons into individual polygons:

4)  Select an individual polygon (or several polygons) in the image and drag the polygon from the image to create a new image in the drawing.

5)  Alternatively, press Delete to delete the selected polygon(s) from the image.

Bitmap conversion

All drawing objects placed into a LibreOffice drawing are vector graphics and these vector graphics can be converted to a bitmap (raster graphic) in PNG format. Any transparency effects in the original vector graphic are lost during conversion even though the PNG format used by LibreOffice Draw supports transparencies.

Use one of the following methods to convert a vector graphic to a bitmap:


No confirmation dialog is provided for a bitmap conversion.