# Mixed pixels Remote sensing image sensor collect energy, which is sampled on to a grid of pixel data. Given the heterogeneity of the surface of the earth and the objects we wish to analyse and identify, it is rare that a single object will match exactly to our grid of pixels in the data. These images below illustrate this. The first image is showing a whale, with the equivalent image pixel grid overlaid. The second image shows that only a handful are pure whale pixels (dark blue), with the remainder being mixed pixels. It is important to consider the presence of mixed pixels when conducting spectral analysis. ![Image: P Fretwell unpublished](/files/psve7gX3vG96exkRCqlg) ![Image: P Fretwell unpublished](/files/p7y1rRTTfurRhj4PQ4w1) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://guides.geospatial.bas.ac.uk/spectral-analysis-of-imagery/mixed-pixels.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.