Std. of Image

This function block computes the standard deviation of pixel values in an image (range 0–255) and displays the result in its interface. It is useful for assessing image contrast, noise level or overall brightness variation.

📥 Inputs

Image Any This input socket accepts any image (grayscale or color). Provide the image you want analyzed.

📤 Outputs

Standard Deviation This output socket delivers a single numeric value: the standard deviation of the image pixel values.

🕹️ Controls

This function block has no interactive controls. It updates its displayed value automatically when image input is provided.

🎯 Features

• Quick numeric feedback on image variability (contrast/noise).

• Live update of displayed value when a new image is provided.

• Works with both grayscale and color images (produces a single summary number).

📝 Usage

1. Connect an image-producing block to the Image Any input. Examples: Camera USB, Load Image, or Video.

2. Read the computed value from the Standard Deviation output or from the block's on-screen label.

3. Use the value to trigger logic, logging or visualization (for example, warn if image is too uniform or too noisy).

⚙️ Evaluation

When the scenario runs and an image arrives at the input, the block calculates the standard deviation of pixel intensities and outputs the numeric result while also updating its display.

💡 Tips and Tricks

• For clearer statistics on a specific area, crop first with Image ROI or Image ROI Select and feed the cropped image to this block.

• To reduce noise impact before measuring, preprocess with Blur or Denoising and then measure the standard deviation.

• Compare this value with Mean Value of Image to better understand image contrast versus overall brightness.

• When analyzing many images or monitoring trends, pipe the output to Scope for live plotting or to Image Logger / CSV Export for recording.

• If image size is large and you only need a quick estimate, downscale with Image Resizer before feeding this block to speed up processing.

• Combine with Image Resolution and Channel Value or Non-zero of Image to add contextual checks (example: ensure image has expected channels or content before trusting the statistic).

🛠️ Troubleshooting

• No value appearing: verify that an upstream block is sending a valid image to Image Any.

• Unexpectedly low or high value: confirm you are measuring the intended region (use Image ROI) and consider preprocessing with Blur or Denoising to remove sensor noise or compression artifacts.

• Want visual inspection: connect the same image source to Show Image to preview the image while checking the statistic.