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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-09 14:45:54 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-09 14:45:54 -0800 |
commit | 96a6de1a541c86e9e67b9c310c14db4099bd1cbc (patch) | |
tree | e77eb0e998e996f53dd0709611bd8cdd8776ee70 /Documentation/media/v4l-drivers/ipu3.rst | |
parent | 36011ddc78395b59a8a418c37f20bcc18828f1ef (diff) | |
parent | 15d90a6ae98e6d2c68497b44a491cb9efbb98ab1 (diff) | |
download | linux-96a6de1a541c86e9e67b9c310c14db4099bd1cbc.tar.bz2 |
Merge tag 'media/v5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab:
- remove sensor drivers that got converted from soc_camera
- remaining soc_camera drivers got moved to staging
- some documentation cleanups and improvements
- the imx staging driver now supports imx7
- the ov9640, mt9m001 and mt9m111 got converted from soc_camera
- the vim2m driver now does what a m2m convert driver expects to do
- epoll() fixes on media subsystems
- several drivers fixes, typos, cleanups and improvements
* tag 'media/v5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (346 commits)
media: dvb/earth-pt1: fix wrong initialization for demod blocks
media: vim2m: Address some coding style issues
media: vim2m: don't use BUG()
media: vim2m: speedup passthrough copy
media: vim2m: add an horizontal scaler
media: vim2m: don't accept YUYV anymore as output format
media: vim2m: add vertical linear scaler
media: vim2m: better handle cap/out buffers with different sizes
media: vim2m: use different framesizes for bayer formats
media: vim2m: add support for VIDIOC_ENUM_FRAMESIZES
media: vim2m: ensure that width is multiple of two
media: vim2m: improve debug messages
media: vim2m: add bayer capture formats
media: a few more typos at staging, pci, platform, radio and usb
media: Documentation: fix several typos
media: staging: fix several typos
media: include: fix several typos
media: common: fix several typos
media: v4l2-core: fix several typos
media: usb: fix several typos
...
Diffstat (limited to 'Documentation/media/v4l-drivers/ipu3.rst')
-rw-r--r-- | Documentation/media/v4l-drivers/ipu3.rst | 151 |
1 files changed, 150 insertions, 1 deletions
diff --git a/Documentation/media/v4l-drivers/ipu3.rst b/Documentation/media/v4l-drivers/ipu3.rst index f89b51dafadd..c9f780404eee 100644 --- a/Documentation/media/v4l-drivers/ipu3.rst +++ b/Documentation/media/v4l-drivers/ipu3.rst @@ -1,3 +1,5 @@ +.. SPDX-License-Identifier: GPL-2.0 + .. include:: <isonum.txt> =============================================================== @@ -355,10 +357,157 @@ https://chromium.googlesource.com/chromiumos/platform/arc-camera/+/master/ The source can be located under hal/intel directory. +Overview of IPU3 pipeline +========================= + +IPU3 pipeline has a number of image processing stages, each of which takes a +set of parameters as input. The major stages of pipelines are shown here: + +.. kernel-render:: DOT + :alt: IPU3 ImgU Pipeline + :caption: IPU3 ImgU Pipeline Diagram + + digraph "IPU3 ImgU" { + node [shape=box] + splines="ortho" + rankdir="LR" + + a [label="Raw pixels"] + b [label="Bayer Downscaling"] + c [label="Optical Black Correction"] + d [label="Linearization"] + e [label="Lens Shading Correction"] + f [label="White Balance / Exposure / Focus Apply"] + g [label="Bayer Noise Reduction"] + h [label="ANR"] + i [label="Demosaicing"] + j [label="Color Correction Matrix"] + k [label="Gamma correction"] + l [label="Color Space Conversion"] + m [label="Chroma Down Scaling"] + n [label="Chromatic Noise Reduction"] + o [label="Total Color Correction"] + p [label="XNR3"] + q [label="TNR"] + r [label="DDR"] + + { rank=same; a -> b -> c -> d -> e -> f } + { rank=same; g -> h -> i -> j -> k -> l } + { rank=same; m -> n -> o -> p -> q -> r } + + a -> g -> m [style=invis, weight=10] + + f -> g + l -> m + } + +The table below presents a description of the above algorithms. + +======================== ======================================================= +Name Description +======================== ======================================================= +Optical Black Correction Optical Black Correction block subtracts a pre-defined + value from the respective pixel values to obtain better + image quality. + Defined in :c:type:`ipu3_uapi_obgrid_param`. +Linearization This algo block uses linearization parameters to + address non-linearity sensor effects. The Lookup table + table is defined in + :c:type:`ipu3_uapi_isp_lin_vmem_params`. +SHD Lens shading correction is used to correct spatial + non-uniformity of the pixel response due to optical + lens shading. This is done by applying a different gain + for each pixel. The gain, black level etc are + configured in :c:type:`ipu3_uapi_shd_config_static`. +BNR Bayer noise reduction block removes image noise by + applying a bilateral filter. + See :c:type:`ipu3_uapi_bnr_static_config` for details. +ANR Advanced Noise Reduction is a block based algorithm + that performs noise reduction in the Bayer domain. The + convolution matrix etc can be found in + :c:type:`ipu3_uapi_anr_config`. +DM Demosaicing converts raw sensor data in Bayer format + into RGB (Red, Green, Blue) presentation. Then add + outputs of estimation of Y channel for following stream + processing by Firmware. The struct is defined as + :c:type:`ipu3_uapi_dm_config`. +Color Correction Color Correction algo transforms sensor specific color + space to the standard "sRGB" color space. This is done + by applying 3x3 matrix defined in + :c:type:`ipu3_uapi_ccm_mat_config`. +Gamma correction Gamma correction :c:type:`ipu3_uapi_gamma_config` is a + basic non-linear tone mapping correction that is + applied per pixel for each pixel component. +CSC Color space conversion transforms each pixel from the + RGB primary presentation to YUV (Y: brightness, + UV: Luminance) presentation. This is done by applying + a 3x3 matrix defined in + :c:type:`ipu3_uapi_csc_mat_config` +CDS Chroma down sampling + After the CSC is performed, the Chroma Down Sampling + is applied for a UV plane down sampling by a factor + of 2 in each direction for YUV 4:2:0 using a 4x2 + configurable filter :c:type:`ipu3_uapi_cds_params`. +CHNR Chroma noise reduction + This block processes only the chrominance pixels and + performs noise reduction by cleaning the high + frequency noise. + See struct :c:type:`ipu3_uapi_yuvp1_chnr_config`. +TCC Total color correction as defined in struct + :c:type:`ipu3_uapi_yuvp2_tcc_static_config`. +XNR3 eXtreme Noise Reduction V3 is the third revision of + noise reduction algorithm used to improve image + quality. This removes the low frequency noise in the + captured image. Two related structs are being defined, + :c:type:`ipu3_uapi_isp_xnr3_params` for ISP data memory + and :c:type:`ipu3_uapi_isp_xnr3_vmem_params` for vector + memory. +TNR Temporal Noise Reduction block compares successive + frames in time to remove anomalies / noise in pixel + values. :c:type:`ipu3_uapi_isp_tnr3_vmem_params` and + :c:type:`ipu3_uapi_isp_tnr3_params` are defined for ISP + vector and data memory respectively. +======================== ======================================================= + +Other often encountered acronyms not listed in above table: + + ACC + Accelerator cluster + AWB_FR + Auto white balance filter response statistics + BDS + Bayer downscaler parameters + CCM + Color correction matrix coefficients + IEFd + Image enhancement filter directed + Obgrid + Optical black level compensation + OSYS + Output system configuration + ROI + Region of interest + YDS + Y down sampling + YTM + Y-tone mapping + +A few stages of the pipeline will be executed by firmware running on the ISP +processor, while many others will use a set of fixed hardware blocks also +called accelerator cluster (ACC) to crunch pixel data and produce statistics. + +ACC parameters of individual algorithms, as defined by +:c:type:`ipu3_uapi_acc_param`, can be chosen to be applied by the user +space through struct :c:type:`ipu3_uapi_flags` embedded in +:c:type:`ipu3_uapi_params` structure. For parameters that are configured as +not enabled by the user space, the corresponding structs are ignored by the +driver, in which case the existing configuration of the algorithm will be +preserved. + References ========== -.. [#f5] include/uapi/linux/intel-ipu3.h +.. [#f5] drivers/staging/media/ipu3/include/intel-ipu3.h .. [#f1] https://github.com/intel/nvt |