Filters & Effects Quick Reference

Image Filters

Basic Adjustments

Brightness

Range: -100 to +100
Formula: $\text{new} = \text{original} + \text{brightness}$
Use: Lighten/darken images
Example: +20 for slightly brighter

Contrast

Range: -100 to +100
Formula: $\text{new} = (\text{original} - 128) \times \text{factor} + 128$
Use: Increase/decrease difference between light and dark
Example: +30 for more dramatic contrast

Saturation

Range: -100 to +100
Formula: Blend between original and grayscale
Use: Make colors more/less vivid
Example: -50 for muted colors, +25 for vibrant

Color Effects

Grayscale Conversion

Luminance Formula: $\text{Gray} = 0.299R + 0.587G + 0.114B$

Use cases:

Black and white photography
Reducing file size
Accessibility improvements
Vintage effects

Sepia Tone

Sepia Formula:

$R_{new} = 0.393R + 0.769G + 0.189B$
$G_{new} = 0.349R + 0.686G + 0.168B$
$B_{new} = 0.272R + 0.534G + 0.131B$

Characteristics:

Warm, brownish tone
Vintage/antique appearance
Popular for portraits

Color Inversion (Negative)

Formula: $\text{new} = 255 - \text{original}$

White becomes black
Black becomes white
Colors become complementary

Artistic Filters

Blur Effects

Gaussian Blur: Smooth, natural blur
Motion Blur: Directional blur effect
Radial Blur: Circular blur from center
Parameters: Radius (1-50 pixels typical)

Sharpen

Unsharp Mask: Most common sharpening
Parameters: Amount, Radius, Threshold
Use: Enhance edge definition
Caution: Can introduce artifacts

Vintage/Retro Effects

Common characteristics:

Reduced saturation
Warm color temperature
Vignetting (dark edges)
Film grain texture
Faded appearance

Filter Combinations

Instagram-style Filters

Valencia:

Increase warmth (+15)
Add slight vignette
Boost contrast (+10)
Reduce saturation (-5)

Nashville:

Warm temperature
Reduce contrast (-10)
Add pink/purple tint
Increase brightness (+5)

Audio Effects

Basic Audio Processing

Volume/Gain

Range: -∞ dB to +20 dB
0 dB: Original level
-6 dB: Half volume
+6 dB: Double volume
Formula: $\text{dB} = 20 \log_{10}(\frac{\text{new}}{\text{original}})$

Normalize

Purpose: Maximize volume without clipping
Process: Find peak, scale to target level
Target: Usually -1 dB to -3 dB

Frequency Effects

Bass Boost

Frequency Range: 20 Hz - 250 Hz
Typical Boost: +3 dB to +6 dB
Use: Enhance low-end for music
Caution: Can cause distortion

Treble Enhancement

Frequency Range: 2 kHz - 20 kHz
Typical Boost: +2 dB to +4 dB
Use: Add clarity and presence
Effect: Brighter, more detailed sound

Equalizer Bands

| Frequency | Description | Effect | |-----------|-------------|--------| | 60 Hz | Sub-bass | Rumble, depth | | 170 Hz | Bass | Warmth, fullness | | 310 Hz | Low-mid | Body, thickness | | 600 Hz | Mid | Presence | | 1 kHz | Upper-mid | Clarity | | 3 kHz | High-mid | Definition | | 6 kHz | Treble | Brightness | | 12 kHz | High treble | Air, sparkle |

Time-based Effects

Echo

Parameters: Delay time, feedback, mix
Delay Time: 50ms - 2000ms
Use: Add space and depth
Example: 250ms delay, 25% feedback

Reverb

Types: Room, Hall, Plate, Spring
Parameters: Size, decay time, damping
Use: Simulate acoustic spaces
Settings:
- Small room: 0.5s decay
- Large hall: 2-4s decay

Noise Processing

Noise Reduction

Process:
1. Analyze noise profile
2. Apply spectral subtraction
3. Smooth transitions
Parameters: Reduction amount, sensitivity
Use: Clean up recordings

Noise Gate

Purpose: Remove background noise during silence
Parameters: Threshold, attack, release
Threshold: -40 dB to -20 dB typical

Text Processing

Case Conversion

Original: "Hello World Example"
UPPERCASE: "HELLO WORLD EXAMPLE"
lowercase: "hello world example"
Title Case: "Hello World Example"
camelCase: "helloWorldExample"
snake_case: "hello_world_example"
kebab-case: "hello-world-example"

Text Extraction

Email Extraction

Regex Pattern:

[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}

Example matches:

user@example.com
test.email+tag@domain.co.uk
name123@sub.domain.org

URL Extraction