Yalantis/uCrop · error · CImgIOException

save_inr(): Unsupported pixel type '%s' for file '%s'

Error message

save_inr(): Unsupported pixel type '%s' for file '%s'

What it means

The INR format stores an explicit pixel type string ('unsigned fixed PIXSIZE=8 bits', 'float PIXSIZE=32/64 bits', etc.); _save_inr() selects inrtype/inrpixsize from the image's pixel_type() and throws CImgIOException when inrpixsize remains <= 0, i.e. the instance's element type has no INR representation. Unlike the null-filename check this fires after type matching, so it indicates a dtype problem, not a path problem.

Source

Thrown at ucrop/src/main/jni/CImg.h:63090

        inrtype = "unsigned fixed\nPIXSIZE=16 bits\nSCALE=2**0";inrpixsize = 2;
      }
      if (!cimg::strcasecmp(pixel_type(),"int16")) {
        inrtype = "fixed\nPIXSIZE=16 bits\nSCALE=2**0"; inrpixsize = 2;
      }
      if (!cimg::strcasecmp(pixel_type(),"uint32")) {
        inrtype = "unsigned fixed\nPIXSIZE=32 bits\nSCALE=2**0";inrpixsize = 4;
      }
      if (!cimg::strcasecmp(pixel_type(),"int32")) {
        inrtype = "fixed\nPIXSIZE=32 bits\nSCALE=2**0"; inrpixsize = 4;
      }
      if (!cimg::strcasecmp(pixel_type(),"float32")) {
        inrtype = "float\nPIXSIZE=32 bits"; inrpixsize = 4;
      }
      if (!cimg::strcasecmp(pixel_type(),"float64")) {
        inrtype = "float\nPIXSIZE=64 bits"; inrpixsize = 8;
      }
      if (inrpixsize<=0)
        throw CImgIOException(_cimg_instance
                              "save_inr(): Unsupported pixel type '%s' for file '%s'",
                              cimg_instance,
                              pixel_type(),filename?filename:"(FILE*)");

      std::FILE *const nfile = file?file:cimg::fopen(filename,"wb");
      CImg<charT> header(257);
      int err = cimg_snprintf(header,header._width,"#INRIMAGE-4#{\nXDIM=%u\nYDIM=%u\nZDIM=%u\nVDIM=%u\n",
                              _width,_height,_depth,_spectrum);
      if (voxel_size)
        err+=cimg_snprintf(header._data + err,128,"VX=%g\nVY=%g\nVZ=%g\n",
                          voxel_size[0],voxel_size[1],voxel_size[2]);
      err+=cimg_snprintf(header._data + err,128,"TYPE=%s\nCPU=%s\n",
                         inrtype,cimg::endianness()?"sun":"decm");
      std::memset(header._data + err,'\n',252 - err);
      std::memcpy(header._data + 252,"##}\n",4);
      cimg::fwrite(header._data,256,nfile);
      cimg_forXYZ(*this,x,y,z) cimg_forC(*this,c) cimg::fwrite(&((*this)(x,y,z,c)),1,nfile);
      if (!file) cimg::fclose(nfile);

View on GitHub (pinned to f788b534b4)

Solutions

  1. Convert to a supported type before saving: img.get_float32().save_inr(filename) or CImg<float>(img).save_inr(...).
  2. Keep 8-bit data by using a format that supports unsigned char natively (PNG, BMP, PNM).
  3. Check pixel_type() before export and reject unsupported types with an app-level message.
  4. Upgrade CImg if a newer version registers additional INR pixel types.

Example fix

// before
CImg<unsigned short> depth(640,480,1,1,0);
depth.save_inr("depth.inr"); // throws

// after
CImg<float> depthf(depth);
depthf.save_inr("depth.inr");
Defensive patterns

Strategy: validation

Validate before calling

static const char* kInrTypes[] = {"uint8","int8","uint16","int16","float32","float64"};
bool ok = false;
for (const char* t : kInrTypes)
  if (!cimg::strcasecmp(img.pixel_type(), t)) { ok = true; break; }
if (!ok) throw std::runtime_error(std::string("INR unsupported for ") + img.pixel_type());

Type guard

template <typename T>
constexpr bool inr_supported() {
  return sizeof(T) == 1 || sizeof(T) == 2 || std::is_floating_point_v<T>;
}

Try / catch

try {
  img.save_inr("vol.inr");
} catch (const CImgIOException& e) {
  std::fprintf(stderr, "converting to float32 for INR: %s\n", e.what());
  CImg<float>(img).save_inr("vol.inr");
}

Prevention

When it happens

Trigger: Calling save_inr() on CImg<unsigned short>, CImg<bool>, or any type whose pixel_type() string matches none of the handled cases (8/16-bit fixed, float32, float64); generic save("file.inr") dispatched from such an instance.

Common situations: Saving 16-bit depth maps or 8-bit masks to .inr; data pipeline switched element type without updating the export step; older CImg with fewer INR type cases.

Related errors

AI-assisted analysis of Yalantis/uCrop@f788b534b4 (2026-09-08). Data as JSON: /api/errors/4bef37c189534ae3. Report an issue: GitHub.