[−][src]Function opencv::imgcodecs::imwrite

pub fn imwrite(
    filename: &str, 
    img: &dyn ToInputArray, 
    params: &VectorOfint
) -> Result<bool>

Saves an image to a specified file.

The function imwrite saves the image to the specified file. The image format is chosen based on the filename extension (see cv::imread for the list of extensions). In general, only 8-bit single-channel or 3-channel (with 'BGR' channel order) images can be saved using this function, with these exceptions:

  • 16-bit unsigned (CV_16U) images can be saved in the case of PNG, JPEG 2000, and TIFF formats
  • 32-bit float (CV_32F) images can be saved in TIFF, OpenEXR, and Radiance HDR formats; 3-channel (CV_32FC3) TIFF images will be saved using the LogLuv high dynamic range encoding (4 bytes per pixel)
  • PNG images with an alpha channel can be saved using this function. To do this, create 8-bit (or 16-bit) 4-channel image BGRA, where the alpha channel goes last. Fully transparent pixels should have alpha set to 0, fully opaque pixels should have alpha set to 255/65535 (see the code sample below).

If the format, depth or channel order is different, use Mat::convertTo and cv::cvtColor to convert it before saving. Or, use the universal FileStorage I/O functions to save the image to XML or YAML format.

The sample below shows how to create a BGRA image and save it to a PNG file. It also demonstrates how to set custom compression parameters: @include snippets/imgcodecs_imwrite.cpp

Parameters

  • filename: Name of the file.
  • img: Image to be saved.
  • params: Format-specific parameters encoded as pairs (paramId_1, paramValue_1, paramId_2, paramValue_2, ... .) see cv::ImwriteFlags

C++ default parameters

  • params: std::vector()