capi.Captcha images
Quality, size, hints and matching the current task.
Source image
Use the PNG or JPEG of the current task. A full-page screenshot, extra margins and re-compression hurt recognition. Keep puzzle fragments and transparent hints as PNG with transparency.
One round, one session
The main image, hints and puzzle fragment must belong to the same round. After the captcha refreshes, earlier data is no longer valid.
Sizes and coordinates
Recognition coordinates refer to the source image. When it is displayed at a different size, the plugin must account for scale and the element's position in the browser. Sizes and formulas are on each type's page.
Sending data
With the plugin, the plugin prepares the request and talks to the server itself. With the direct API the picture goes as base64 in the image field or as raw bytes in the request body — see «Direct API».