Working with Images

1. Introduction to Digital Images

Definition: A digital image is a representation of an image in a finite set of digital values (0 or 1), known as pixels.
Appeal: Images provide visual appeal and are often easier to comprehend than pure text because the brain responds quickly to colors.
File Formats: Common extensions for graphic files include GIF, JPG, JPEG, PNG, and BMP.

There are four primary ways to insert a stored image file into a document:

Insert Image Dialog Box: Navigate to Insert > Image from the menu bar, select the file, and click “Open”.
Drag and Drop: Open a file browser, select the image, and drag it directly into the desired position in the document.
Copy and Paste: Use keyboard shortcuts (Ctrl+C to copy and Ctrl+V to paste) or right-click context menus to move images via the clipboard.
Linking: Instead of embedding the image, you can check the “Link” option in the Insert Image dialog. This stores a reference to the file, reducing document size and allowing the image to update if the source file changes.

The Image Toolbar (View > Toolbars > Image) provides various tools for modification:

Image Filters: Includes 11 filters such as Invert (reverses colors), Smooth (softens contrast), Sharpen (increases contrast), Remove Noise, and Charcoal Sketch.
Image Mode: Changes the image to grayscale, black and white, or a watermark.
Cropping: Used to cut off non-desirable parts of an image.
Resizing: Adjusting the size by dragging sizing handles. Corner handles resize width and height simultaneously.
Rotating: Using the rotate tool and corner handles to turn the image to a specific angle.
Color and Transparency: Adjustments for primary colors (RGB), brightness, contrast, gamma, and transparency percentage.

Invert: This tool reverses the color values of a colored image; if the image is grayscale, it inverts the brightness values.
Smooth: It softens the contrast of an image. Selecting this tool opens a dialogue box to adjust specific parameters.
Sharpen: This filter increases the contrast of the image.
Remove Noise: It is used to eliminate single, stray pixels from the image.
Solarisation: Primarily used for photographs, this filter reverses the tones—making dark areas appear light and light areas appear dark. It includes a dialogue box for parameter adjustment.
Aging: This simulates the effect of time on a picture. Clicking it opens a dialogue box to adjust the intensity of the effect.
Posterise: This makes a picture look like a painting by reducing the number of colors. It also features a dialogue box for adjustments.
Charcoal Sketch: This filter transforms the image into a charcoal sketch.
Relief: This tool creates a shadow effect by adjusting a virtual light source. A dialogue box is used to set the parameters.
Mosaic: This joins groups of pixels into single areas of one color to create a pixelated effect. It includes a dialogue box for adjustment.

LibreOffice Writer includes a set of drawing tools for creating designs, flowcharts, or diagrams.

Drawing Toolbar: Enabled via View > Toolbars > Drawing. It contains tools for lines, rectangles, circles, basic shapes, stars, and callouts.
Object Properties: The Drawing Object Properties Toolbar allows for customizing line color, fill color, width, and styles.
Grouping: Multiple overlapping shapes can be grouped to behave as a single entity. This ensures that changes (like moving or resizing) apply to all members of the group simultaneously.

Correct positioning in relation to text is managed through four main settings:

Arrangement: Determines the order of overlapping objects (e.g., Bring to Front, Send to Back, To Foreground, To Background).
Anchoring: Sets a reference point so the image moves with a specific page, paragraph, character, or frame.
Alignment: Controls the horizontal or vertical placement of the image relative to its anchor.
Text Wrapping: Defines how text flows around the image. Options include Wrap off (text above/below), Page Wrap (text flows around), and Wrap through (image superimposed on text).