Yalantis/uCrop · error · CImgArgumentException

load_pfm(): Specified filename is (null).

Error message

load_pfm(): Specified filename is (null).

What it means

This is an argument-contract check in CImg<T>::_load_pfm(): the loader requires either an open FILE* or a non-null filename. If both are null, there is nothing to read from, so it throws CImgArgumentException before touching the file system.

Source

Thrown at ucrop/src/main/jni/CImg.h:57771

    //! Load image from a PFM file \newinstance.
    static CImg<T> get_load_pfm(const char *const filename) {
      return CImg<T>().load_pfm(filename);
    }

    //! Load image from a PFM file \overloading.
    CImg<T>& load_pfm(std::FILE *const file) {
      return _load_pfm(file,0);
    }

    //! Load image from a PFM file \newinstance.
    static CImg<T> get_load_pfm(std::FILE *const file) {
      return CImg<T>().load_pfm(file);
    }

    CImg<T>& _load_pfm(std::FILE *const file, const char *const filename) {
      if (!file && !filename)
        throw CImgArgumentException(_cimg_instance
                                    "load_pfm(): Specified filename is (null).",
                                    cimg_instance);

      std::FILE *const nfile = file?file:cimg::fopen(filename,"rb");
      char pfm_type;
      CImg<charT> item(16384,1,1,1,0);
      int W = 0, H = 0, err = 0;
      double scale = 0;
      while ((err=std::fscanf(nfile,"%16383[^\n]",item.data()))!=EOF && (*item=='#' || !err)) std::fgetc(nfile);
      if (cimg_sscanf(item," P%c",&pfm_type)!=1) {
        if (!file) cimg::fclose(nfile);
        throw CImgIOException(_cimg_instance
                              "load_pfm(): PFM header not found in file '%s'.",
                              cimg_instance,
                              filename?filename:"(FILE*)");
      }
      while ((err=std::fscanf(nfile," %16383[^\n]",item.data()))!=EOF && (*item=='#' || !err)) std::fgetc(nfile);
      if ((err=cimg_sscanf(item," %d %d",&W,&H))<2) {

View on GitHub (pinned to f788b534b4)

Solutions

1. Pass a valid filename string to load_pfm, e.g. img.load_pfm("scene.pfm").
2. Open the file yourself and pass the FILE*: FILE* f=fopen(path,"rb"); img.load_pfm(f).
3. Check why the filename is null (failed getenv/lookup) and provide a default or abort early with a clear error.
4. Guard the call: if (!path) { report; return; } before invoking the loader.
5. Catch CImgArgumentException in calling code that deals with optional paths.

Example fix

// before
const char* path = getenv("HDR_FILE"); // may be NULL
img.load_pfm(path);
// after
const char* path = getenv("HDR_FILE");
if (path) {
  img.load_pfm(path);
} else {
  std::fprintf(stderr, "HDR_FILE not set\n");
}

if (path == nullptr || path[0] == '\0') {
  throw std::invalid_argument("PFM path must be set before load_pfm");
}

bool hasSource(std::FILE* f, const char* name) { return f != nullptr || name != nullptr; }

try {
  img.load_pfm(path);
} catch (cimg_library::CImgArgumentException& e) {
  std::cerr << "No PFM source given: " << e.what() << "\n";
}

When it happens

Trigger: Calling load_pfm(nullptr) or load_pfm(nullptr, nullptr); passing a filename variable that is NULL (e.g. from getenv or an uninitialized char*); programmatically constructing a CImg load chain where the source path was never set.

Common situations: Configuration lookups returning NULL for the image path; forgetting to default-initialize a filename buffer; calling the FILE*-overload without opening the file first.

Related errors

• load_jpeg(): Specified filename is (null).
• load_jxl(): Specified filename is (null).
• load_magick(): Specified filename is (null).
• load_pfm(): PFM header not found in file '%s'.
• load_pfm(): WIDTH and HEIGHT fields are undefined in file '%

AI-assisted analysis of Yalantis/uCrop@f788b534b4 (2026-09-08). Data as JSON: /api/errors/da14eef10d99b45d. Report an issue: GitHub.