Constant turbojpeg_sys::TJPARAM_TJPARAM_LOSSLESS

pub const TJPARAM_TJPARAM_LOSSLESS: TJPARAM = 15;

Lossless JPEG

Value

• 0 [default for compression] The JPEG image is (decompression) or will be (compression) lossy/DCT-based.
• 1 The JPEG image is (decompression) or will be (compression) lossless/predictive.

In most cases, compressing and decompressing lossless JPEG images is considerably slower than compressing and decompressing lossy JPEG images. Also note that the following features are not available with lossless JPEG images:

• Colorspace conversion (lossless JPEG images always use #TJCS_RGB, #TJCS_GRAY, or #TJCS_CMYK, depending on the pixel format of the source image)
• Chrominance subsampling (lossless JPEG images always use #TJSAMP_444)
• JPEG quality selection
• DCT/IDCT algorithm selection
• Progressive entropy coding
• Arithmetic entropy coding
• Compression from/decompression to planar YUV images
• Decompression scaling
• Lossless transformation

@see #TJPARAM_LOSSLESSPSV, #TJPARAM_LOSSLESSPT