Yalantis/uCrop · error · CImgArgumentException

"[" cimg_appname "_math_parser] CImg<%s>: Function 'draw()':

Error message

"[" cimg_appname "_math_parser] CImg<%s>: Function 'draw()': Target vector (%lu values) and its specified target geometry (%d,%d,%d,%d) (%lu values) do not match."

What it means

CImg's math-parser 'draw()' opcode validates the target image vector against the user-supplied geometry (w,h,d,s). When the vector's element count (sizD) is smaller than w*h*d*s, it cannot be reshaped into the requested geometry, so CImgArgumentException is thrown to prevent out-of-bounds access.

Source

Thrown at ucrop/src/main/jni/CImg.h:30167

        const double *const ptrs = &_mp_arg(7) + 1;
        const unsigned int
          sizD = (unsigned int)mp.opcode[2],
          sizS = (unsigned int)mp.opcode[8];
        const int
          w = (int)_mp_arg(3), h = (int)_mp_arg(4), d = (int)_mp_arg(5), s = (int)_mp_arg(6),
          x = (int)_mp_arg(9), y = (int)_mp_arg(10), z = (int)_mp_arg(11), c = (int)_mp_arg(12);
        int dx = (int)mp.opcode[13], dy = (int)mp.opcode[14], dz = (int)mp.opcode[15], dc = (int)mp.opcode[16];
        dx = (unsigned int)dx==~0U?w:(int)_mp_arg(13);
        dy = (unsigned int)dy==~0U?h:(int)_mp_arg(14);
        dz = (unsigned int)dz==~0U?d:(int)_mp_arg(15);
        dc = (unsigned int)dc==~0U?s:(int)_mp_arg(16);

        if (w<=0 || h<=0 || d<=0 || s<=0)
          throw CImgArgumentException("[" cimg_appname "_math_parser] CImg<%s>: Function 'draw()': "
                                      "Invalid specified target vector geometry (%d,%d,%d,%d).",
                                      mp.imgin.pixel_type(),w,h,d,s);
        if (sizD<(ulongT)w*h*d*s)
          throw CImgArgumentException("[" cimg_appname "_math_parser] CImg<%s>: Function 'draw()': "
                                      "Target vector (%lu values) and its specified target geometry (%d,%d,%d,%d) "
                                      "(%lu values) do not match.",
                                      mp.imgin.pixel_type(),sizD,w,h,d,s,(ulongT)w*h*d*s);
        if (dx<=0 || dy<=0 || dz<=0 || dc<=0)
          throw CImgArgumentException("[" cimg_appname "_math_parser] CImg<%s>: Function 'draw()': "
                                      "Invalid specified sprite geometry (%d,%d,%d,%d).",
                                      mp.imgin.pixel_type(),dx,dy,dz,dc);
        if (sizS<(ulongT)dx*dy*dz*dc)
          throw CImgArgumentException("[" cimg_appname "_math_parser] CImg<%s>: Function 'draw()': "
                                      "Sprite vector (%lu values) and its specified sprite geometry (%d,%d,%d,%d) "
                                      "(%lu values) do not match.",
                                      mp.imgin.pixel_type(),sizS,dx,dy,dz,dc,(ulongT)dx*dy*dz*dc);

        CImg<doubleT> D(ptrd,w,h,d,s,true);
        const CImg<doubleT> S(ptrs,dx,dy,dz,dc,true);
        const float opacity = (float)_mp_arg(17);

        if (mp.opcode[18]!=~0U) { // Opacity mask specified

View on GitHub (pinned to f788b534b4)

Solutions

Increase the target vector so it contains at least w*h*d*s values, or
Reduce the specified geometry (w,h,d,s) so its product does not exceed the vector size sizD
Verify sizes at runtime with .size() before invoking draw() in the expression

Example fix

// before
draw(ind,vec_target,4,4,1,1,...); // target has 8 values
// after
draw(ind,vec_target,2,4,1,1,...); // geometry matches 8-value vector

Defensive patterns

Strategy: validation

Validate before calling

if (target.size() < (unsigned long)w*h*d*s) { /* fix geometry or vector */ }

Prevention

Compute geometry from the vector's actual size instead of hard-coding
Assert vector.size() >= w*h*d*s before building draw() expressions
Centralize dimension constants shared between vector creation and draw() calls

When it happens

Trigger: Calling draw(...) in a CImg math expression/formula where the target vector has fewer values than the product of the specified dimensions w*h*d*s (e.g. draw with target geometry 4x4 but a 8-element vector).

Common situations: Hand-written math_parser expressions with mismatched dimension arguments; dynamically computed sizes that under-run the declared geometry; porting scripts between image sizes without updating geometry constants.

Understand the failure class

Background: Tensor shape mismatch errors ("must have shape", "expected shape ... got ..."): when tensor dimensions disagree with what an op or layer was told to expect — this error's family across 6 libraries.

Related errors

AI-assisted analysis of Yalantis/uCrop@f788b534b4 (2026-09-08). Data as JSON: /api/errors/9b63e37eee630f2d. Report an issue: GitHub.