Image Convolution Interactive Tool
See how a 3x3 convolution kernel slides over pixels, multiplies neighboring values, and creates a feature map. This is the same core idea behind early CNN layers for edges, textures, shapes, and visual patterns.
Active kernel
Edge Detection
Output pixel = sum of neighboring pixels multiplied by the kernel weights.
Image mode
Apply the kernel to an image
Use the generated teaching image or upload a PNG, JPG, or WebP. Processing stays local in your browser.
Current image: Generated teaching image
Pixel-grid mode
Watch the convolution calculation
Input patch
Kernel weights
Center pixel example
Raw sum: 651.00
Clamped output: 255
Output feature map
Center-pixel multiplication
CNN intuition
Convolution turns local pixel neighborhoods into feature maps.
In a neural network, kernels are learned from data instead of manually selected. Early layers often respond to edges and textures; deeper layers combine those responses into shapes, objects, and task-specific patterns.
Teaching note
This tool uses hand-picked kernels for learning. Real CNN filters are initialized and then learned through backpropagation, so the network discovers useful patterns from training examples rather than relying on fixed filters.