Image loading/saving utilities using stb_image library. More...
#include "epaper/color/color_manager.hpp"#include "epaper/core/errors.hpp"#include "epaper/core/framebuffer_concepts.hpp"#include "epaper/core/types.hpp"#include <cstddef>#include <expected>#include <span>#include <string_view>#include <vector>
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Classes | |
| class | epaper::ImageIO |
| Utilities for loading/saving images and converting formats. More... | |
| struct | epaper::ImageIO::ImageResult |
Namespaces | |
| namespace | epaper |
Detailed Description
Image loading/saving utilities using stb_image library.
Provides high-level interface for loading images from disk and saving framebuffers as PNG files. Uses stb_image for format support.
Supported Formats:
Loading (stb_image):
├─ PNG (Portable Network Graphics) - lossless, alpha support
├─ JPEG/JPG (Joint Photographic Experts Group) - lossy, no alpha
├─ BMP (Windows Bitmap) - uncompressed
├─ TGA (Truevision Targa) - gaming formats
├─ GIF (Graphics Interchange Format) - animation (first frame only)
├─ PSD (Photoshop Document) - composited image only
└─ HDR (Radiance RGBE) - high dynamic range
Saving (stb_image_write):
└─ PNG (Portable Network Graphics) - lossless, alpha support
Pixel Format Conversions:
Input Image → RGB/RGBA → Color Enum → DisplayMode → Framebuffer
↓ ↓ ↓ ↓ ↓
PNG/JPG stb_image ColorManager PixelCodec set_pixel()
Channel Modes:
- 1 channel: Grayscale (Y)
- 3 channels: RGB (interleaved: RGBRGBRGB...)
- 4 channels: RGBA (interleaved: RGBARGBARGBA...)
Framebuffer Export:
framebuffer_to_rgb(): Convert any FramebufferLike to RGB image- Used by MockDriver for test verification
- Enables visual debugging (save framebuffer state as PNG)
Use Cases:
- Load logos/icons for display on e-paper
- Export framebuffer state for debugging
- Batch convert images to e-paper color modes
- Generate test fixtures (compare rendered vs expected)
Error Handling:
- All operations return
std::expected<T, Error>for fallible I/O - Common errors: File not found, unsupported format, out of memory
