Perpixel

Perpixel refers to operations or processes that are applied to individual pixels. The concept is central to computer graphics, image processing, and display technology, where each pixel’s data is treated independently or in combination with near neighbors, depending on the algorithm. The term is often written as per-pixel or per-pixel, and may appear in brand names or product descriptions as well.

In rendering, per-pixel shading calculates lighting, color, and material response for each pixel rather than at vertices. This approach yields more accurate and detailed results than per-vertex techniques, such as Gouraud shading, which interpolate vertex colors across a surface. Per-pixel shading is typically implemented in fragment or pixel shaders, using shading languages like GLSL or HLSL. Modern pipelines emphasize per-fragment processing and can incorporate complex lighting models, texture lookups, and post-processing effects on a per-pixel basis.

In image processing, per-pixel algorithms operate on the value of each pixel, often independently. Examples include brightness and contrast adjustment, thresholding, color space conversion, and many filtering operations. While many per-pixel operations are simple and highly parallelizable, others incorporate neighborhood information, blending local and global data to achieve effects such as denoising or edge detection.

Per-pixel processing is fundamental to hardware acceleration on GPUs and modern image processing hardware. It enables high throughput and parallelism, but efficiency depends on data locality, memory bandwidth, and shader or kernel design. The term is commonly used descriptively; when capitalized or stylized as a brand name, it may refer to a specific product or company rather than a general concept.