Inspect
Pass an image or mask through unchanged and read its technical properties.
Inspect is a diagnostic tap. It passes whatever you wire into it straight through, pixel for pixel, and reports everything ArcBrush knows about that image in the Parameters panel: size, channels, bit depth, per-channel values, alpha coverage, color space, content bounds, and which file the pixels came from. Drop it anywhere in a chain (it does not have to be at the end) and keep building downstream of it.
At the top of the panel, a single health line gives you the verdict: Healthy, Empty, Contains non-finite values, Contains negative values, Contains overbright values, or Statistics not computed. When more than one problem is present, the most serious one leads and the rest are noted as counts.
What it reports
Section titled “What it reports”| Section | What it tells you |
|---|---|
| Format | Pixel dimensions, aspect ratio, single-channel or RGBA, 8-bit or 32-bit float, predicted and resident memory (an image spilled to disk says so), and whether the document itself is in 8-bit or 32-bit mode. |
| Channel statistics | Minimum, maximum, average, and standard deviation per channel (or one Value row for a single-channel image). |
| Float health | Counts of NaN, infinite, negative, and overbright values, with the coordinates of the first pixel where each occurs. 32-bit images only. |
| Alpha | Whether an alpha channel exists, its range, and pixel counts for fully transparent, partially transparent, and fully opaque areas. |
| Color management | The tagged color space, whether it is scene-referred or display-encoded, whether it is stored linearly or with a curve, and its luma weighting. |
| Batch | Per-frame names and colors, a summary of whether the frames agree on size, depth, channels, and color space, and total memory. Appears only when the wire carries a batch. |
| Content bounds | The smallest rectangle containing everything not fully transparent, and how much of that rectangle is actually filled. |
| Source | The file the pixels came from, its digest, what kind of source it is, and (for formats that carry them) which layer or AOV was used. |
| Histogram | Per-channel, luminance, and alpha distributions. Off by default; turn on Show Histogram. |
Values are always shown on a 0 to 1 scale, never 0 to 255. An 8-bit image’s middle gray reads as 0.502, which is what lets you compare an 8-bit and a 32-bit image directly, and what lets an overbright float value show up honestly as 1.35 instead of being clipped to 1.0 the way a preview would show it.
Reading a batch
Section titled “Reading a batch”On a batch, the Batch section’s summary covers every frame without reading a single pixel, but only the frame you pick in the Frame selector is analyzed for statistics, alpha, color management, content bounds, histogram, and source. This is deliberate: scanning hundreds of frames just because you opened the panel would be slow. Switching frames is instant, changes nothing in your document, and creates no undo step.
Non-zero color under zero alpha
Section titled “Non-zero color under zero alpha”The Alpha section counts pixels that carry a visible color but are marked fully invisible. A high count usually means color is leaking through a “hidden” area, which shows up as a colored fringe or halo once that image is composited without special handling. The Alpha association row always reads “Not tracked”: ArcBrush does not record whether an image’s colors have already been multiplied by alpha. To find out, look for a Premult or Unpremult node upstream.
Parameters
Section titled “Parameters”Pins
Inspect
Run the per-channel statistics reduction (min/max/mean/std dev, float health, alpha coverage, content bounds) on the pipeline worker as this node cooks.
On a batch, only the selected frame is analyzed.
Turning this off leaves Format, Color Management, and Batch fully populated. Only the sections that read a pixel pass go blank.
Compute per-channel, luminance, and alpha histograms alongside the statistics reduction.
Off by default: a histogram is extra worker cost this node does not pay unless asked.
Usage Tips
Section titled “Usage Tips”- A chain going wrong somewhere in the middle is what Inspect is for. Tap it in at a few points and read where the values actually went bad, rather than guessing from the preview.
- Before exporting to an 8-bit format, check the Float health section for overbright values. Anything above 1.0 clips straight to white on the way out; tame it with a Clamp node first if you want to keep the detail.
- NaN or infinite values almost always mean something upstream divided by zero, commonly dividing color by alpha where alpha is exactly zero. Inspect gives you the first pixel’s coordinates so you can go straight there.
- Use it to confirm a mask input really is a single-channel image rather than an RGBA image with its color discarded.
- The Copy report button puts the full read-out, including the complete file path and digest, onto the clipboard as plain text, the fastest way to hand over exact details in a bug report.
- The histogram here is deliberately literal: it counts every stored value, including the color underneath fully transparent pixels, which the Levels, Curves, and preview histograms hide on purpose. Do not expect it to match them on an image with transparency.
- Turn off Compute Statistics to leave only the sections that cost nothing to show (Format, Color management, Batch, and Source).