Pros of Guetzli

• Produces significantly smaller JPEG files (20-30% reduction) while maintaining visual quality
• Optimized for perceptual quality, resulting in visually pleasing images
• Suitable for high-quality image compression in web applications

Cons of Guetzli

• Slower compression speed compared to libwebp
• Limited to JPEG format, while libwebp supports multiple formats
• Higher memory usage during compression process

Code Comparison

Guetzli (C++):

guetzli::Params params;
params.butteraugli_target = 0.5;
guetzli::ProcessJpegData(params, jpg_data, jpg_data_len, &output_data);

libwebp (C):

WebPConfig config;
WebPConfigInit(&config);
config.quality = 75;
WebPEncode(&config, &picture, &output);

Both libraries offer simple APIs for image compression, but Guetzli focuses on JPEG optimization while libwebp provides broader format support. Guetzli's approach emphasizes perceptual quality and file size reduction, whereas libwebp offers faster compression and more versatile format options. The choice between the two depends on specific project requirements, such as compression speed, supported formats, and desired output quality.

Pros of mozjpeg

• Better compression for JPEG images, resulting in smaller file sizes
• Maintains high image quality while reducing file size
• Optimized for web use, improving page load times

Cons of mozjpeg

• Limited to JPEG format, while libwebp supports multiple formats
• Slower encoding process compared to libwebp
• Less widespread adoption and browser support than WebP format

Code Comparison

mozjpeg:

cinfo.optimize_coding = TRUE;
jpeg_set_quality(&cinfo, quality, TRUE);
jpeg_simple_progression(&cinfo);

libwebp:

WebPConfig config;
WebPConfigInit(&config);
config.quality = quality;
config.method = 6;  // Slowest but best compression

Both libraries offer simple APIs for configuring compression settings. mozjpeg focuses on optimizing JPEG encoding, while libwebp provides options for WebP format compression.

mozjpeg is ideal for projects requiring high-quality JPEG compression, especially for web use. libwebp offers a more versatile solution with support for multiple formats and potentially faster encoding, but may have slightly lower compression ratios for JPEG images compared to mozjpeg.

Pros of libjpeg-turbo

• Faster JPEG compression and decompression compared to libwebp
• Wider compatibility with existing JPEG-based systems and software
• Smaller file sizes for photographic images in some cases

Cons of libjpeg-turbo

• Limited to JPEG format, lacking support for modern image formats
• Lower compression efficiency for non-photographic images compared to WebP

Code Comparison

libjpeg-turbo:

jpeg_create_compress(&cinfo);
jpeg_stdio_dest(&cinfo, outfile);
jpeg_set_defaults(&cinfo);
jpeg_set_quality(&cinfo, quality, TRUE);
jpeg_start_compress(&cinfo, TRUE);

libwebp:

WebPConfig config;
WebPConfigInit(&config);
config.quality = quality;
WebPEncode(&config, &picture);

The code snippets demonstrate the basic setup for compression in both libraries. libjpeg-turbo uses a more verbose approach with multiple function calls, while libwebp offers a more streamlined API with fewer function calls required for basic encoding.

Both libraries are widely used and have their strengths. libjpeg-turbo excels in JPEG processing and is ideal for systems that primarily work with JPEG images. libwebp, on the other hand, offers a more modern image format with better compression for certain types of images and support for features like animation and alpha transparency.

Pros of libavif

• Better compression efficiency, resulting in smaller file sizes for similar quality
• Support for HDR and wide color gamut images
• More advanced features like multi-layer images and animations

Cons of libavif

• Slower encoding and decoding times compared to libwebp
• Less widespread browser support, especially for older versions
• Larger library size and more complex implementation

Code Comparison

libavif encoding example:

avifEncoder * encoder = avifEncoderCreate();
avifEncoderSetCodecChoice(encoder, AVIF_CODEC_CHOICE_AOM);
avifEncoderWrite(encoder, image, &raw);
avifEncoderDestroy(encoder);

libwebp encoding example:

WebPConfig config;
WebPConfigInit(&config);
WebPPicture picture;
WebPPictureInit(&picture);
WebPEncode(&config, &picture);

Both libraries offer C APIs for encoding and decoding images. libavif's API is more object-oriented, while libwebp's API is more procedural. libavif provides more configuration options for advanced use cases, but libwebp's API is generally simpler for basic encoding tasks.

Pros of libheif

• Supports HEIF format, which offers better compression and quality than WebP
• Provides both encoding and decoding capabilities for HEIF/HEIC images
• Offers more advanced features like HDR support and multi-image containers

Cons of libheif

• Less widespread browser support compared to WebP
• Potentially higher computational requirements for encoding/decoding
• Smaller community and ecosystem compared to WebP

Code Comparison

libheif example:

heif_context* ctx = heif_context_alloc();
heif_context_read_from_file(ctx, input_filename, NULL);
heif_image_handle* handle;
heif_context_get_primary_image_handle(ctx, &handle);
heif_image* img;
heif_decode_image(handle, &img, heif_colorspace_RGB, heif_chroma_interleaved_RGB, NULL);

libwebp example:

WebPDecoderConfig config;
WebPInitDecoderConfig(&config);
WebPDecode(data, data_size, &config);
uint8_t* output = config.output.u.RGBA.rgba;
int width = config.output.width;
int height = config.output.height;

Both libraries provide C APIs for decoding images, but libheif's API is more verbose due to its support for more complex image formats and features. libwebp's API is simpler for basic decoding tasks.

Pros of pngquant

• Specializes in PNG optimization, offering excellent compression for PNG files
• Supports alpha channel preservation, crucial for transparent images
• Faster processing times for PNG files compared to libwebp

Cons of pngquant

• Limited to PNG format, while libwebp supports multiple image formats
• May result in some quality loss due to lossy compression, whereas libwebp offers lossless options
• Less flexibility in terms of output formats compared to libwebp

Code Comparison

pngquant:

void pngquant_image(png24_image *input_image, png8_image *output_image, 
                    const quant_options *options) {
    // Quantization logic here
}

libwebp:

int WebPEncode(const WebPConfig* config, WebPPicture* picture) {
    // Encoding logic here
}

The code snippets show the core functions for image processing in each library. pngquant focuses on quantization for PNG images, while libwebp provides a more general encoding function for WebP format.