> For the complete documentation index, see [llms.txt](https://guide.cryosparc.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guide.cryosparc.com/processing-data/all-job-types-in-cryosparc/particle-picking/job-blob-picker-tuner.md). # Job: Blob Picker Tuner ## Description The Blob Picker Tuner finds optimal blob sizes, shapes, and thresholds for particle picking by comparing picks to a small number of manually selected examples. It does so by performing a grid search of the parameters available to the Blob Picker and Inspect Picks job and computing the agreement with the user picks. It then takes the optimal parameters and performs a full search on all of the input micrographs. Read a tutorial on the Blob Picker Tuner [here](/processing-data/tutorials-and-case-studies/tutorial-blob-picker-tuner.md). **Limitations:** The Blob Picker Tuner can not discriminate particles better than the regular Blob Picker, but makes the process of identifying useful parameters much easier. For the Blob Picker Tuner, the number of labelled particles is important. Labelling too many particles may introduce bias into the Blob Picker based on the human bias of picking. On the other hand, labelling too few particles may result in poor picks. Somewhere from 15-40 particles picks is recommended, but more may be needed for difficult datasets. Neighbouring particles should be picked for manual input to ensure the tuner has information about particle spacing. Read more in the tutorial, here. ## Input * Aligned and CTF-estimated micrographs * Particle picks on one or more of the above micrographs ## Common **Parameters** * **Minimum template diameter (A):** The minimum template size that the grid search will consider. * **Maximum template diameter (A):** The maximum template size that the grid search will consider. * **Steps:** The number of steps the search will take between the minimum and maximum diameters. More steps means a finer resolution in parameter space, with the cost of increased (quadratic) computation time. * **Particle agreement distance (A):** Determines the distance at which a user-provided pick is considered the same as a blob-pick. The tuner works best when this parameter is roughly the size of the protein. ## Output * Particles * Micrographs ## **Common Next Steps** * 2D Classification and Select 2D to generate templates for Template picking --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## 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, and the optional `goal` query parameter: ``` GET https://guide.cryosparc.com/processing-data/all-job-types-in-cryosparc/particle-picking/job-blob-picker-tuner.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. 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.