2.12.4. V4L2_META_FMT_VSP1_HGO (‘VSPH’)¶
Renesas R-Car VSP1 1-D Histogram Data
2.12.4.1. Description¶
This format describes histogram data generated by the Renesas R-Car VSP1 1-D Histogram (HGO) engine.
The VSP1 HGO is a histogram computation engine that can operate on RGB, YCrCb or HSV data. It operates on a possibly cropped and subsampled input image and computes the minimum, maximum and sum of all pixels as well as per-channel histograms.
The HGO can compute histograms independently per channel, on the maximum of the three channels (RGB data only) or on the Y channel only (YCbCr only). It can additionally output the histogram with 64 or 256 bins, resulting in four possible modes of operation.
- In 64 bins normal mode, the HGO operates on the three channels independently to compute three 64-bins histograms. RGB, YCbCr and HSV image formats are supported.
- In 64 bins maximum mode, the HGO operates on the maximum of the (R, G, B) channels to compute a single 64-bins histogram. Only the RGB image format is supported.
- In 256 bins normal mode, the HGO operates on the Y channel to compute a single 256-bins histogram. Only the YCbCr image format is supported.
- In 256 bins maximum mode, the HGO operates on the maximum of the (R, G, B) channels to compute a single 256-bins histogram. Only the RGB image format is supported.
Byte Order. All data is stored in memory in little endian format. Each cell in the tables contains one byte.
Offset | Memory | ||||
---|---|---|---|---|---|
[31:24] | [23:16] | [15:8] | [7:0] | ||
0 | R/Cr/H max [7:0] | R/Cr/H min [7:0] | |||
4 | G/Y/S max [7:0] | G/Y/S min [7:0] | |||
8 | B/Cb/V max [7:0] | B/Cb/V min [7:0] | |||
12 | R/Cr/H sum [31:0] | ||||
16 | G/Y/S sum [31:0] | ||||
20 | B/Cb/V sum [31:0] | ||||
24 | R/Cr/H bin 0 [31:0] | ||||
... | |||||
276 | R/Cr/H bin 63 [31:0] | ||||
280 | G/Y/S bin 0 [31:0] | ||||
... | |||||
532 | G/Y/S bin 63 [31:0] | ||||
536 | B/Cb/V bin 0 [31:0] | ||||
... | |||||
788 | B/Cb/V bin 63 [31:0] |
Offset | Memory | ||||
---|---|---|---|---|---|
[31:24] | [23:16] | [15:8] | [7:0] | ||
0 | max(R,G,B) max [7:0] | max(R,G,B) min [7:0] | |||
4 | max(R,G,B) sum [31:0] | ||||
8 | max(R,G,B) bin 0 [31:0] | ||||
... | |||||
260 | max(R,G,B) bin 63 [31:0] |
Offset | Memory | ||||
---|---|---|---|---|---|
[31:24] | [23:16] | [15:8] | [7:0] | ||
0 | Y max [7:0] | Y min [7:0] | |||
4 | Y sum [31:0] | ||||
8 | Y bin 0 [31:0] | ||||
... | |||||
1028 | Y bin 255 [31:0] |
Offset | Memory | ||||
---|---|---|---|---|---|
[31:24] | [23:16] | [15:8] | [7:0] | ||
0 | max(R,G,B) max [7:0] | max(R,G,B) min [7:0] | |||
4 | max(R,G,B) sum [31:0] | ||||
8 | max(R,G,B) bin 0 [31:0] | ||||
... | |||||
1028 | max(R,G,B) bin 255 [31:0] |