examples

Gopiq Examples

This directory contains comprehensive examples demonstrating the features and capabilities of the gopiq image processing library.

Files

Sample Image

• sample_image.png - A colorful test image with geometric shapes (800x600 pixels)

Example Programs

1. basic_example.go - Demonstrates basic image operations

   • Loading images from bytes
   • Grayscale conversion
   • Resizing
   • Cropping
   • Chaining operations

2. watermark_example.go - Shows text watermarking capabilities

   • Different watermark positions (top-left, top-right, bottom-left, bottom-right, center)
   • Custom styling (colors, sizes, offsets)
   • Multiple watermark styles

3. grayscale_example.go - Performance comparison of grayscale methods

   • Regular grayscale conversion
   • Fast parallel grayscale conversion
   • Custom performance options
   • Timing comparisons

4. resize_example.go - Comprehensive resize operations

   • Various size formats (thumbnail, medium, large, square, wide, tall)
   • Aspect ratio preservation
   • Chaining with other operations

5. crop_example.go - Image cropping demonstrations

   • Corner crops
   • Center crops
   • Grid-based cropping
   • Error handling for invalid crops

6. comprehensive_example.go - Complete feature demonstration

   • All major features in one example
   • Performance comparisons
   • Error handling
   • Memory efficiency
   • Different output formats

Running the Examples

To run any example:

cd examples
go run <example_name>.go

For example:

go run basic_example.go
go run watermark_example.go
go run comprehensive_example.go

Generated Output Files

Each example generates various output images demonstrating different operations:

Basic Example Outputs

• output_grayscale.png - Grayscale version of the sample image
• output_resized.png - Resized to 400x300
• output_cropped.png - Cropped 200x150 portion

Watermark Example Outputs

• watermark_top_left.png - Watermark in top-left position
• watermark_top_right.png - Watermark in top-right position
• watermark_bottom_left.png - Watermark in bottom-left position
• watermark_bottom_right.png - Watermark in bottom-right position
• watermark_center.png - Watermark in center position
• watermark_custom_style.png - Custom styled watermark

Grayscale Example Outputs

• grayscale_regular.png - Standard grayscale conversion
• grayscale_fast.png - Optimized parallel grayscale conversion
• grayscale_custom_perf.png - Custom performance options

Resize Example Outputs

• resize_thumbnail.png - 100x75 thumbnail
• resize_medium.png - 400x300 medium size
• resize_large.png - 1200x900 large size
• resize_square.png - 500x500 square format
• resize_wide.png - 800x200 wide format
• resize_tall.png - 200x800 tall format
• resize_chain_grayscale.png - Resize + grayscale chain
• resize_aspect_ratio.png - Aspect ratio preserved resize

Crop Example Outputs

• crop_top_left.png - Top-left corner crop
• crop_top_right.png - Top-right corner crop
• crop_bottom_left.png - Bottom-left corner crop
• crop_bottom_right.png - Bottom-right corner crop
• crop_center_square.png - Center square crop
• crop_center_rect.png - Center rectangle crop
• crop_small_detail.png - Small detail crop
• crop_wide_strip.png - Wide strip crop
• crop_tall_strip.png - Tall strip crop
• crop_chain_resize.png - Crop + resize chain
• crop_grid_*.png - 4x4 grid of crops

Comprehensive Example Outputs

• comprehensive_basic.png - Basic operations result
• comprehensive_watermark_*.png - Various watermark styles
• comprehensive_grayscale_*.png - Performance comparison results
• comprehensive_pipeline.png - Complex processing pipeline result
• comprehensive_format.png/.jpg - Different output formats
• comprehensive_efficiency_*.png - Memory efficiency test results

Key Features Demonstrated

• Image Loading: Loading images from byte arrays
• Grayscale Conversion: Both regular and optimized parallel methods
• Resizing: High-quality Catmull-Rom interpolation
• Cropping: Precise rectangular cropping with bounds checking
• Watermarking: Text watermarks with customizable positioning and styling
• Chaining: Fluent API for combining multiple operations
• Performance: Parallel processing and performance optimization
• Error Handling: Comprehensive error checking and reporting
• Format Support: PNG and JPEG output formats
• Memory Efficiency: Object pooling and efficient memory usage

Performance Notes

The examples include performance comparisons showing:

• Fast grayscale conversion can be 1.4x to 5x faster than regular conversion
• Parallel processing is most beneficial for larger images
• Custom performance options allow fine-tuning for specific use cases

Error Handling

Examples demonstrate proper error handling for:

• Invalid crop coordinates
• Negative dimensions
• Empty watermark text
• Out-of-bounds operations

All examples include comprehensive error checking and informative error messages.