gchq/CyberChef · warning · OperationError

Error applying filter to image.

Error message

Error applying filter to image. (${err})

What it means

Wraps any error from the greyscale()/sepia() filter call or the subsequent getBuffer() inside Image Filter's inner try/catch. Surfaces the underlying Jimp error in the message so the user can tell whether filtering or encoding failed.

Solutions

1. Read the embedded error to distinguish filter vs buffer failure.
2. Pre-convert exotic colour spaces/bit depths to 8-bit RGB PNG/JPEG.
3. Downscale large images or process outside a worker.
4. Try the other filter type to isolate a codec-specific bug.

Example fix

// before: 16-bit CMYK JPEG trips the filter
op.run(cmykJpegBuf, ["Greyscale"]);
// after: convert to 8-bit sRGB first
op.run(srgbPngBuf, ["Greyscale"]);

function assertFilterType(t) {
  if (!['Greyscale', 'Sepia'].includes(t)) {
    throw new RangeError(`Unsupported filter type: ${t}`);
  }
}

function isSupportedFilterType(t) {
  return t === 'Greyscale' || t === 'Sepia';
}

try {
  result = await filter.run(buf, [filterType]);
} catch (e) {
  if (e instanceof OperationError && /applying filter/i.test(e.message)) {
    // try the other filter, or pre-convert colour space
    result = await filter.run(await toSrgbPng(buf), [filterType]);
  } else throw e;
}

When it happens

Trigger: Jimp filter rejecting on an unusual colour space or bit depth; getBuffer failing for an unsupported output mime; memory exhaustion on a large image in a worker; a Jimp regression in sepia/greyscale.

Common situations: 16-bit or CMYK JPEG that Jimp mishandles; animated GIF where frame handling throws; oversized image; Jimp version bug.

Related errors

• Error adjusting image brightness or contrast.
• Error adding text to image.
• Error adjusting image hue / saturation / lightness.
• Error blurring image.
• Error changing image opacity.

AI-assisted analysis of gchq/CyberChef@4290ea7539 (2026-08-13). Data as JSON: /api/errors/d67b5f1c4160690c. Report an issue: GitHub.

Appendix: source

Thrown at src/core/operations/ImageFilter.mjs:78

                    "Applying " +
                        filterType.toLowerCase() +
                        " filter to image...",
                );
            if (filterType === "Greyscale") {
                image.greyscale();
            } else {
                image.sepia();
            }

            let imageBuffer;
            if (image.mime === "image/gif") {
                imageBuffer = await image.getBuffer(JimpMime.png);
            } else {
                imageBuffer = await image.getBuffer(image.mime);
            }
            return imageBuffer.buffer;
        } catch (err) {
            throw new OperationError(
                `Error applying filter to image. (${err})`,
            );
        }
    }

    /**
     * Displays the blurred image using HTML for web apps
     * @param {ArrayBuffer} data
     * @returns {html}
     */
    present(data) {
        if (!data.byteLength) return "";
        const dataArray = new Uint8Array(data);

        const type = isImage(dataArray);
        if (!type) {
            throw new OperationError("Invalid file type.");
        }

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