mini_tiff

This is a super simple header only library to read/write TIFF files supporting 8, 16 bits per channel (unsigned shorts), and 32 bits per channel (floats). I'm using it to read and save files in 16bits/float and check the results inside Photoshop for example.

Features

• Support mono, RGB and RGB+Alpha files
• Support 8,16 bits or 32 bits per channel (uint8/uint16/float)
• Support Big and Little endian formats
• Only uncompressed TIFFs
• Minimal metadata is saved
• Data is assumed to be in a linear buffer when saving it
• No exceptions. API will return true if everything is ok, false if there is an error.
• For 4 channels images, pixel layout is Red, Green, Blue, Alpha
• No memory allocations
• You can also recover basic metadata using the info command

Install

This is a header only libray, just copy the mini_tiff.h somewhere in your code. No need to link any library.

Save a Tiff

Assuming you have your RGB image somewhere. The provided pointer must contain width x height x number_of_channels x bits/channel ( 2 in this example, because we want a 16 bits per component tiff )

  bool is_ok = MiniTiff::save(out_filename, img.width, img.height, 3, 16, img.data());

Load a Tiff

Load a tiff takes a bit longer. You need to provide the input filename, and a lambda which will receive the parsed basic parameters from the tiff, and a FileReader object, which has a method readBytes to read bytes directly into your container. No need to close the file.

If file can't be parsed the lambda will not get called and a false is returned.

  ImageRGB rgb;
  bool is_ok = MiniTiff::load(infilename, [&](int w, int h, int num_components, int bits_per_component, MiniTiff::FileReader& f) -> bool {
    // Confirm the tiff contains the format we expect in this concrete example
    if (bits_per_component != 16 || num_components != 3)
      return false;
    // Redimension my image buffer
    rgb.resize(w, h);
    // Read the data from f.
    return f.readBytes( rgb.data(), w * h * num_components * (bits_per_component / 8));
    });

List TAGs

Basic metadata can be recovered by providing a lambda that will be called for each IFDTag. The helper function Tags::asStr will return a const char* for the basic tags.

  MiniTiff::info( ifilename, []( uint16_t id, uint32_t value, uint32_t value_type, uint32_t num_elems  ) {
    printf( "  %04x : %32s : %6d (%08x) x%d elems of type %d \n", id, MiniTiff::Tags::asStr( id ), value, value, num_elems, value_type);
  });