Yalantis/uCrop · error · CImgArgumentException

"[" cimg_appname "_math_parser] CImg<%s>: Function 'da_remov

Error message

"[" cimg_appname "_math_parser] CImg<%s>: Function 'da_remove()': Specified image #%u of size (%d,%d,%d,%d) cannot be used as dynamic array%s."

What it means

mp_da_remove() removes elements from a dynamic array stored as a single-column image. Before removing, it validates that image #ind is 1xNx1xC with a valid element counter in its last row. This error is thrown when the target image cannot be interpreted as a dynamic array (wrong dimensions or corrupt counter).

Source

Thrown at ucrop/src/main/jni/CImg.h:26401

                if (img[index]<img[index_parent]) {
                  T *ptr0 = img.data(0,index), *ptr1 = img.data(0,index_parent);
                  cimg_forC(img,c) { cimg::swap(*ptr0,*ptr1); ptr0+=img._height; ptr1+=img._height; }
                  index = index_parent;
                }
                else break;
              }
          }
        img[img._height - 1] = (T)cimg::uint2float(siz + nb_elts);
        return cimg::type<double>::nan();
      }

      static double mp_da_remove(_cimg_math_parser& mp) {
        mp_check_list(mp,"da_remove");
        const unsigned int ind = (unsigned int)cimg::mod((int)_mp_arg(2),mp.imglist.width());
        CImg<T> &img = mp.imglist[ind];
        int siz = img?(int)cimg::float2uint((float)img[img._height - 1]):0;
        if (img && (img._width!=1 || img._depth!=1 || siz<0 || siz>img.height() - 1))
          throw CImgArgumentException("[" cimg_appname "_math_parser] CImg<%s>: Function 'da_remove()': "
                                      "Specified image #%u of size (%d,%d,%d,%d) cannot be used as dynamic array%s.",
                                      mp.imgout.pixel_type(),ind,
                                      img.width(),img.height(),img.depth(),img.spectrum(),
                                      img._width==1 && img._depth==1?"":" (contains invalid element counter)");
        if (!siz)
          throw CImgArgumentException("[" cimg_appname "_math_parser] CImg<%s>: Function 'da_remove()': "
                                      "Dynamic array is empty.",
                                      mp.imgout.pixel_type());
        int
          start0 = mp.opcode[3]==~0U?siz - 1:_mp_arg(3),
          end0 = mp.opcode[4]==~0U?start0:_mp_arg(4),
          start = start0<0?start0 + siz:start0,
          end = end0<0?end0 + siz:end0;
        if (start<0 || start>=siz || end<0 || end>=siz || start>end)
          throw CImgArgumentException("[" cimg_appname "_math_parser] CImg<%s>: Function 'da_remove()': "
                                      "Invalid starting (%d) and ending (%d) positions "
                                      "(not ordered, in range -%d...%d).",
                                      mp.imgout.pixel_type(),start0,end0,siz,siz - 1);

View on GitHub (pinned to f788b534b4)

Solutions

  1. Confirm the image index in da_remove refers to a dynamic array created and maintained by da_* functions.
  2. Rebuild the array (re-insert elements with da_insert) if its structure was altered by other operations.
  3. Check that the element counter (last row) is within 0..height-1; correct or reinitialize the array.
  4. Guard the expression with da_size(#ind) checks before calling da_remove.

Example fix

// before
 da_remove(#2,0)
// after: verify index and array validity first
 if (da_size(#2)>0, da_remove(#2,0), error("image #2 is not a valid dynamic array"))
Defensive patterns

Strategy: validation

Validate before calling

// Verify array validity and non-zero size before da_remove
const siz = isValidDynamicArray(images[ind]) ? images[ind].counter : -1;
if (siz <= 0) throw new Error('da_remove: array empty or invalid');

Type guard

function isRemovableDa(img) { return Boolean(img) && img.width === 1 && img.depth === 1 && img.counter > 0 && img.counter <= img.height - 1; }

Try / catch

try { evalMath('da_remove(#' + ind + ',' + start + ',' + end + ')'); } catch (e) { if (String(e).includes('da_remove')) { log('invalid array at index ' + ind); rebuild(ind); } else throw e; }

Prevention

When it happens

Trigger: Calling da_remove(#ind,...) where the image at index ind is not a 1-column/1-depth image, is empty (img==0 handled by siz=0 path), or its stored element count is negative or exceeds height-1.

Common situations: Operating on an image that was overwritten by regular drawing/fill operations; wrong image index in a multi-image expression; constructing the array manually with an incorrect counter value.

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/29bd1eb27343223f. Report an issue: GitHub.