Yalantis/uCrop · error · CImgArgumentException

"[" cimg_appname "_math_parser] CImg<

Error message

"[" cimg_appname "_math_parser] CImg<%s>: Function 'store()': Specified image dimensions (%d,%d,%d,%d) are invalid."

What it means

The math parser 'store()' function serializes an image into a memory buffer using caller-provided dimensions w,h,d,s. If any dimension is negative the geometry is meaningless, so a CImgArgumentException is thrown with the four requested dimensions before any serialization happens.

Solutions

  1. Clamp each dimension with max(0, expr) or validate w,h,d,s >= 0 before calling store().
  2. Fix the arithmetic producing negative dimensions (check start/end ordering in differences).
  3. Pass the actual image's dimensions (w,h,d,s) directly instead of computed values.
  4. Catch CImgArgumentException and report the requested geometry to the caller.

Example fix

// before: store(buf, w2-w1, h2-h1, d, s)
// after:  store(buf, max(0,w2-w1), max(0,h2-h1), d, s)
Defensive patterns

Strategy: validation

Validate before calling

if (w < 0 || h < 0 || d < 0 || s < 0)
  throw std::runtime_error("store() dimensions must be non-negative");

Try / catch

try { img.evaluate(storeExpr); } catch (const CImgArgumentException& e) { log("store() geometry invalid: " << e.what()); }

Prevention

When it happens

Trigger: store(...,w,h,d,s,is_compressed) where one of _mp_arg(7..9) evaluates to a negative value — e.g. computing dimensions as a difference like w2-w1 that underflows, or a variable that was initialized to a negative sentinel.

Common situations: Dimension arithmetic bugs (end-before-start subtraction); formula parameterization errors where a user passes -1 as 'auto' sentinel but store() doesn't support sentinels; mismatches when storing cropped sub-images.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

AI-assisted analysis of Yalantis/uCrop@f788b534b4 (2026-09-08). Data as JSON: /api/errors/174c5da81ae4a814. Report an issue: GitHub.

Appendix: source

Thrown at ucrop/src/main/jni/CImg.h:29843

      }

#ifdef cimg_mp_func_store
      static double mp_store(_cimg_math_parser& mp) {
        const double
          *ptr1 = &_mp_arg(2),
          *ptr2 = &_mp_arg(4) + 1;
        const unsigned int
          siz1 = (unsigned int)mp.opcode[3],
          siz2 = (unsigned int)mp.opcode[5];
        const int
          w = (int)_mp_arg(6),
          h = (int)_mp_arg(7),
          d = (int)_mp_arg(8),
          s = (int)_mp_arg(9);

        const bool is_compressed = (bool)_mp_arg(10);
        if (w<0 || h<0 || d<0 || s<0)
          throw CImgArgumentException("[" cimg_appname "_math_parser] CImg<%s>: Function 'store()': "
                                      "Specified image dimensions (%d,%d,%d,%d) are invalid.",
                                      pixel_type(),w,h,d,s);
        CImg<charT> ss(siz2 + 1);
        cimg_for_inX(ss,0,ss.width() - 2,i) ss[i] = (char)ptr2[i];
        ss.back() = 0;
        if (siz1) cimg_mp_func_store(ptr1 + 1,siz1,
                                     (unsigned int)w,(unsigned int)h,(unsigned int)d,(unsigned int)s,
                                     is_compressed,ss._data);
        else cimg_mp_func_store(ptr1,1,(unsigned int)w,(unsigned int)h,(unsigned int)d,(unsigned int)s,
                                is_compressed,ss._data);
        return cimg::type<double>::nan();
      }
#endif

      static double mp_s2v(_cimg_math_parser& mp) {
        const double *ptrs = &_mp_arg(2);
        const ulongT siz = (ulongT)mp.opcode[3];
        longT ind = (longT)_mp_arg(4);

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