Adobe Photoshop Fundamentals: Raster Graphics and Image Editing

Posted on Jan 4, 2026 in Software Engineering

1. Graphics Fundamentals

Graphics are visual representations used to communicate ideas, messages, or data.

• Types of Graphics

  • Raster: Pixel-based images (e.g., photos).
  • Vector: Mathematical path-based images (e.g., logos).
• Uses: Branding, advertising, web design, UI/UX, and digital art.
• Software: Adobe Photoshop (Raster), Adobe Illustrator (Vector), CorelDRAW, Canva, and Figma.

2. Adobe Photoshop Introduction and Interface

Adobe Photoshop is the industry-standard software for raster image editing and digital art.

Interface Elements

• Menu Bar: Top-level access to files, filters, and settings.
• Toolbar: Houses selection, drawing, and retouching tools.
• Layers Panel: The “stack” where different elements are managed.
• Options Bar: Changes based on the tool currently selected.

Common Image Formats

• PSD: Photoshop’s native format (preserves layers).
• JPEG: Compressed, widely compatible (no transparency).
• PNG: Supports transparency, lossless compression.
• TIFF: High-quality format used in professional printing.

3. Image Manipulation: Selection and Basic Tools

Selection tools define which part of the image you want to edit.

• Marquee Tool: Selects rectangular or elliptical areas.
• Lasso Tool: Freehand selection (Standard, Polygonal for straight lines, Magnetic for edges).
• Magic Wand: Selects areas based on color similarity.
• Inverting Selection: Swaps the selected area with the unselected area (Ctrl+Shift+I).
• Layers: The “transparent sheets” that allow you to edit elements independently.

Advantage: Non-destructive editing (using layers).

Limitation: Poor selection can lead to “jagged” edges or unrealistic compositions.

4. Painting and Retouching Tools

These tools modify the pixels directly to enhance or distort the image.

Essential Tools

• Brush Tool: Paints strokes using various shapes and textures.
• Eraser Tool: Removes pixels (or reverts them to the background color).
• Fill Tool (Paint Bucket): Fills a selected area with a solid color or pattern.
• Focus Tools: Blur (softens), Sharpen (defines edges), Smudge (drags pixels like wet paint).
• Tonal Tools: Dodge (lightens), Burn (darkens), Sponge (changes saturation).

5. Image Transformation and Advanced Retouching

This stage involves changing the physical properties of an image or fixing imperfections.

Transformations

• Free Transform (Ctrl+T): Allows you to scale, rotate, and move.
• Distort/Perspective/Warp: Used to wrap images around 3D objects or fix architectural angles.
• Canvas vs. Image Size: Image size changes the content; Canvas size changes the “workspace” area.

Advanced Retouching

• Clone Stamp: Copies pixels from one area to another precisely.
• Healing Brush: Blends the texture of the source with the lighting of the target.
• Patch Tool: Replaces a large selected area with pixels from another area.

6. Color Correction and Typography

Managing color is vital for professional output.

• Image Modes: RGB (for screens), CMYK (for printing), Grayscale.
• Adjustments: Levels, Curves, and Hue/Saturation are used to fix lighting and color casts.
• Text Tool: Allows for “Type Layers.” You can adjust leading (line spacing), tracking (character spacing), and use Warp Text for arched or wavy styles.

7. Advanced Effects and Filters

• Blending Modes: Determines how a layer interacts with the layer beneath it (e.g., Multiply, Overlay, Screen).
• Liquify: A powerful filter used to push/pull pixels (common in portrait retouching).
• Vanishing Point: Allows you to paint or paste objects while maintaining the perspective of the scene.

8. Drawing and Vector Paths (Pen Tool)

Photoshop includes vector-like capabilities through the Pen Tool.

• Pen Tool: Creates “Paths” using anchor points.
• Paths vs. Selections: Paths are mathematical and can be saved; they can be converted into high-precision selections or “Stroked” with a brush.

Advantage: Maximum precision for cutting out complex objects (like hair or machinery).

Limitation: High learning curve for beginners.

Advantages and Limitations Summary