Yalantis/uCrop · error · CImgIOException

load_cimg(): Invalid specified size (%u,%u,%u,%u) of image %

Error message

load_cimg(): Invalid specified size (%u,%u,%u,%u) of image %u in file '%s'

What it means

In the region-of-interest overload CImgList::load_cimg(filename,n0,...,c1), each image's header line must parse as exactly four unsigned dimensions '%u %u %u %u'; otherwise this error is thrown (CImg.h:66902). Same corruption/truncation cause as the non-ROI variant, but no compressed-size field is expected.

Source

Thrown at ucrop/src/main/jni/CImg.h:66902

                                     const unsigned int z1, const unsigned int c1) {
      return CImgList<T>().load_cimg(file,n0,n1,x0,y0,z0,c0,x1,y1,z1,c1);
    }

    CImgList<T>& _load_cimg(std::FILE *const file, const char *const filename,
                            const unsigned int n0, const unsigned int n1,
                            const unsigned int x0, const unsigned int y0,
                            const unsigned int z0, const unsigned int c0,
                            const unsigned int x1, const unsigned int y1,
                            const unsigned int z1, const unsigned int c1) {
#define _cimg_load_cimg_case2(Ts1,Ts2,Ts3,Tss) \
      if (!loaded && ((Ts1 && !cimg::strcasecmp(Ts1,str_pixeltype)) || \
                      (Ts2 && !cimg::strcasecmp(Ts2,str_pixeltype)) || \
                      (Ts3 && !cimg::strcasecmp(Ts3,str_pixeltype)))) { \
        for (unsigned int l = 0; l<=nn1; ++l) { \
          j = 0; while ((i=std::fgetc(nfile))!='\n' && i>=0) tmp[j++] = (char)i; tmp[j] = 0; \
          W = H = D = C = 0; \
          if (cimg_sscanf(tmp,"%u %u %u %u",&W,&H,&D,&C)!=4) \
            throw CImgIOException(_cimglist_instance \
                                  "load_cimg(): Invalid specified size (%u,%u,%u,%u) of image %u in file '%s'", \
                                  cimglist_instance, \
                                  W,H,D,C,l,filename?filename:"(FILE*)"); \
          if (W*H*D*C>0) { \
            if (l<nn0 || nx0>=W || ny0>=H || nz0>=D || nc0>=C) cimg::fseek(nfile,W*H*D*C*sizeof(Tss),SEEK_CUR); \
            else { \
              const unsigned int \
                _nx1 = nx1==~0U?W - 1:nx1, \
                _ny1 = ny1==~0U?H - 1:ny1, \
                _nz1 = nz1==~0U?D - 1:nz1, \
                _nc1 = nc1==~0U?C - 1:nc1; \
              if (_nx1>=W || _ny1>=H || _nz1>=D || _nc1>=C) \
                throw CImgArgumentException(_cimglist_instance \
                                            "load_cimg(): Invalid specified coordinates " \
                                            "[%u](%u,%u,%u,%u) -> [%u](%u,%u,%u,%u) " \
                                            "because image [%u] in file '%s' has size (%u,%u,%u,%u).", \
                                            cimglist_instance, \
                                            n0,x0,y0,z0,c0,n1,x1,y1,z1,c1,l,filename?filename:"(FILE*)",W,H,D,C); \

View on GitHub (pinned to f788b534b4)

Solutions

  1. Re-obtain an intact .cimg file and verify header lines look like 'W H D C'.
  2. Confirm the file you opened is the CImg-format dataset, not another format.
  3. Hexdump the first lines and repair or regenerate the header.

Example fix

// before
imgs.load_cimg(path, 0,1, 0,63, 0,63, 0,0, 0,2); // throws: truncated header

// after
if (verifyCimgHeaders(path)) // check each line parses as 4 uints
  imgs.load_cimg(path, 0,1, 0,63, 0,63, 0,0, 0,2);
else
  reDownloadDataset(path);
Defensive patterns

Strategy: validation

Validate before calling

bool roiHeaderParses(const char* path) {
  std::FILE* f = std::fopen(path, "rb"); if (!f) return false;
  char line[256] = {0};
  bool ok = std::fgets(line, sizeof line, f) != nullptr; // list header
  unsigned N, W, H, D, C;
  if (ok) std::sscanf(line, "%u", &N);
  for (unsigned l = 0; ok && l < N; ++l) {
    if (!std::fgets(line, sizeof line, f)) { ok = false; break; }
    ok = std::sscanf(line, "%u %u %u %u", &W, &H, &D, &C) == 4;
  }
  std::fclose(f);
  return ok;
}

Try / catch

try {
  imgs.load_cimg(path, n0,n1, x0,x1, y0,y1, z0,z1, c0,c1);
} catch (cimg_library::CImgIOException& e) {
  logError("bad .cimg size header for ROI load: %s", e.what());
  reExportDataset(path);
}

Prevention

When it happens

Trigger: Calling load_cimg(file, n0,n1, x0,x1, y0,y1, z0,z1, c0,c1) on a .cimg file whose per-image header has missing or non-numeric dimension fields (sscanf != 4).

Common situations: Truncated downloads; concatenated partial .cimg files; wrong file passed while intending another; header lines altered by text-mode transfer.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

AI-assisted analysis of Yalantis/uCrop@f788b534b4 (2026-09-08). Data as JSON: /api/errors/fef904eaca2e3d70. Report an issue: GitHub.