Yalantis/uCrop · error · CImgIOException

load_pfm(): WIDTH (%d) and HEIGHT (%d) fields are invalid in

Error message

load_pfm(): WIDTH (%d) and HEIGHT (%d) fields are invalid in file '%s'.

What it means

load_pfm() additionally validates that the parsed WIDTH and HEIGHT are positive. If either dimension is <= 0 (e.g. negative from a sign typo or zero from an unfilled field), it throws CImgIOException listing the offending values, since a zero/negative-sized image cannot be allocated.

Source

Thrown at ucrop/src/main/jni/CImg.h:57797

      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) {
        if (!file) cimg::fclose(nfile);
        throw CImgIOException(_cimg_instance
                              "load_pfm(): WIDTH and HEIGHT fields are undefined in file '%s'.",
                              cimg_instance,
                              filename?filename:"(FILE*)");
      } else if (W<=0 || H<=0) {
        if (!file) cimg::fclose(nfile);
        throw CImgIOException(_cimg_instance
                              "load_pfm(): WIDTH (%d) and HEIGHT (%d) fields are invalid in file '%s'.",
                              cimg_instance,W,H,
                              filename?filename:"(FILE*)");
      }
      if (err==2) {
        while ((err=std::fscanf(nfile," %16383[^\n]",item.data()))!=EOF && (*item=='#' || !err)) std::fgetc(nfile);
        if (cimg_sscanf(item,"%lf",&scale)!=1)
          cimg::warn(_cimg_instance
                     "load_pfm(): SCALE field is undefined in file '%s'.",
                     cimg_instance,
                     filename?filename:"(FILE*)");
      }
      std::fgetc(nfile);
      const bool is_color = (pfm_type=='F'), is_inverted = (scale>0)!=cimg::endianness();
      if (is_color) {
        assign(W,H,1,3,(T)0);
        CImg<floatT> buf(3*W);
        T *ptr_r = data(0,0,0,0), *ptr_g = data(0,0,0,1), *ptr_b = data(0,0,0,2);

View on GitHub (pinned to f788b534b4)

Solutions

1. Inspect the header lines: line 2 must be 'W H' (positive ints) and line 3 the scale (+1.0 or -1.0).
2. Fix the exporter so the scale value is on its own line after the dimensions.
3. Correct hand-edited dimensions to positive integers.
4. Add a pre-check in the caller: read the header and reject W<=0 || H<=0 before load_pfm.
5. Catch CImgIOException to surface 'invalid PFM dimensions' with the parsed values.

Example fix

// before
out << "PF\n" << w << " " << scale << "\n"; // scale leaked into dims
// after
out << "PF\n" << w << " " << h << "\n" << scale << "\n";

bool pfmDimsValid(const char* path) {
  std::ifstream f(path);
  std::string l1, l2; std::getline(f, l1); std::getline(f, l2);
  int w=0, h=0;
  return std::sscanf(l2.c_str(), "%d %d", &w, &h) == 2 && w > 0 && h > 0;
}

bool positiveDims(int w, int h) { return w > 0 && h > 0; }

try {
  img.load_pfm(path);
} catch (cimg_library::CImgIOException& e) {
  std::cerr << "Invalid PFM dimensions: " << e.what() << "\n";
}

When it happens

Trigger: load_pfm() on a file whose dimension line parses as two numbers but with W<=0 or H<=0: dimension line accidentally merged with the scale line (e.g. '-1.0' parsed as height), hand-edited headers, or generator bugs emitting 0 or negative dimensions.

Common situations: Writing PFM by hand where the endianness/scale line '-1.0' got misplaced onto the dimension line; uninitialized variables in a custom PFM exporter; test fixtures with 0x0 dimensions.

Understand the failure class

Background: "value must be between 0 and 1" / "out of range" / "must not be negative" errors: fixing range-validation failures across open-source libraries — this error's family across 42 libraries.

Related errors

• load_pfm(): Specified filename is (null).
• load_pfm(): PFM header not found in file '%s'.
• load_pfm(): WIDTH and HEIGHT fields are undefined in file '%
• load_pfm(): SCALE field is undefined in file '%s'.
• load(): Failed to open file '%s'.

AI-assisted analysis of Yalantis/uCrop@f788b534b4 (2026-09-08). Data as JSON: /api/errors/3930af9da8abfd64. Report an issue: GitHub.