Point Grey Research Knowledge Base

Article 104 - Relationship between color processing and number of bits per pixel.

Issue:
Relationship between color processing and number of bits per pixel.

Solution:
When selecting different stipple formats (with the flycaptureSetColorTileFormat() function), this does not affect the programming of the CCD sensor’s Bayer tile mapping. The Bayer tiling on the chip is fixed - when setting different stipple formats, this simply changes the interpretation of the image pixels for color processing.

When color processing is disabled via the flycaptureSetColorProcessingMethod() function, an 8-bit per pixel image is delivered (unless the camera is in 16-bit mode, or Y16, then it's 16 bits/pixel), so for a 640x480 image, 640 * 480 * 1 byte of memory is used. Also, when calling any of the flycaptureStippledTo*() functions, the 8 bit image is upsampled to 24 or 32 bits. For example, the flycaptureStippledtoBGR() function yields 24-bit BGR (in Windows format, where R and B are reversed), while flycaptureStippledToBGRU() yields 32-bit BGRU pixels (where U stands for Unused - although it usually stands for Alpha, but the byte doesn’t contain any meaningful information).

The call to flycaptureGrabImage() always returns the raw 8-bit Bayer stippled image (unless the camera is in Y16 mode), then as a secondary processing step, a call to flycaptureStippledToBGR*() retrieves the color buffer.

Related Articles:
1.) Different color processing algorithms.
2.) Writing color processing software and color interpolation algorithms.
3.) How is color processing performed on my camera’s images?
4.) PGR FlyCapture SDK color processing algorithm performance.
5.) How to determine and interpret the Bayer Tile pixel format of a PGR camera.
6.) Achieving greater color balance across multiple cameras


Article ID:
104
Published:
12:00:00 AM
Last Modified:
4/3/2009 11:41:17 AM

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