K510_ISP_Tuning_Tool_Guides.md

K510 ISP Tuning Tool Guides

Document version: V1.0.0

Published: 2022-03-31

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# preface **Document purpose** This document is an ISP Tuning Tool documentation.

Reader Objects

The primary audience for this document is experienced software engineers, image algorithm engineers, system designers, and system integrators who want to implement proprietary applications and drivers.

Revision history The revision history accumulates a description of each document update. The latest version of the document contains updates for all previous versions.

The version number	Modified by	Date of revision	Revision Notes
V1.0.0	System software groups	2022-03-31	SDK V1.6 released

**Contents**

[TOC]

Introduction to the ISP Tuning Tool Framework

This section describes the ISP tuning tools and descriptions of the data streams that are provided to the upper-level processors to control the overall ISP image optimization.

+----------------------------------------------------+
|                                                    |
|                      K510                          |
|                                                    |
|    +-------+        +--------------------------+   |
|    |       |        |                          |   |
|    |  ISP  +------> |        v4l2_drm.out      |   |
|    |       |        |                          |   |
|    +-------+        +-------------+------------+   |
|                                   |                |
|                                   |                |
|    +-----------------+            |                |
|    |                 |            |                |
|    |   isp-tuningd   | <----------+                |
|    |                 |                             |
|    +^-+--------------+                             |
|     | |                                            |
|     | |                                            |
+----------------------------------------------------+
      | |
      | |
+-------------------------------+
|     | |                       |
|     | |       PC              |
|     | |                       |
|    ++-v------------------+    |
|    |                     |    |
|    |  ISP Tuning Tool    |    |
|    |                     |    |
|    +---------------------+    |
|                               |
+-------------------------------+

Tune the tool traffic

The communication protocol can be found in the documentation in the client code repository, and the tool consists of two parts, one is the client isp-tuningd running on the PC, the program is located in the /app/mediactl_lib/isp-tuningd, and the other part is the server running on the K510. By default, TCP's port 9982 is used for communication.

client

The ISP Tuning Tool is an application that runs on a PC. In addition to being able to set registers, AWB calibration and CCM calibration are also supported.

Server-side

isp-tuningd receives a yuv image (NV12) in size of 3133440 bytes from the standard input and broadcasts it to all clients, we can use v4l2_drm, it will automatically start isp-tuningd and send in the image data, the specific usage is consistent with the v4l2_drm. We can run it with the following command

cd /app/mediactl_lib
# use camera 0
./v4l2_drm.out -t 0 -f video_drm_1080x1920.conf

# use camera 1
./v4l2_drm.out -t 1 -f video_drm_1080x1920_r2k.conf

If you don't need to view the picture, just launch isp-tuningd

/app/mediactl_lib/isp-tuningd

ISP tuning options

Many registers and tables are provided in the K510 ISP for control and tuning. The setting of the ISP hardware registers is very important for image quality. At present, on the K510 platform, the image tuning process is only implemented through TCP Socket.

Tuning tool main window

This section describes the features of these panels on the tuning window.

Figure 3-1 shows the entire operator panel on the tuning window

• Panel 1 is themenuthat can optionally load the configured ISP file or perform calibration.
• Panel 2 is the connection control panel, fill in the IP address and port number of the development board (default port 9982) and click the green connect button to connect.
• Panel 3 is theregister panel, if you need to set or read the register is not in this one, you can use this panel to set and read.
• Panel 4 is a tuning parameter selection panel, the user can select various parameters or groups of parameters according to the panel prompt text, the registers of these selections will be displayed on panel 5.
• Panel 5 is the Tuning Parameter Settings panel, which is used to set or obtain parameter values from the tuning server.
• Panel 6 is an image display panel, which displays the image output by the ISP and can click the pause button in the middle when it is not necessary to play all the time.

THE ISP Tuning Tool does notautomatically acquire all register values after connecting, and if you need to get all register values, you can click theRead button on the right side of the connection control panel to pull all the current register values.

Calibration & Calibration

This section describes instructions for calibration and calibration using ISP tuning tools, including Automatic White Balance (AWB), Color Correction Matrix (CCM), Gamma, and Lens Shadows (LSC).

AWB

Preparations

1. Standard light box with standard D65 light source
2. Standard 24 color card, currently only X-RITE color card is supported
3. A camera ready for calibration can output a sensor original image or a processed image
4. ISP also only open the black level correction and de-mosaic algorithm module, CSC and other format conversion modules must pay attention to symmetry (matrix is inverse matrix), in addition to noise reduction, sharpening and other modules have little impact, but also try to close, nonlinear modules and color processing modules (GAMMA, wide dynamic, AWB, CCM, saturation adjustment, etc.) must be turned off

Gets the image

1. The camera is aimed at the 24 color card, make sure the 24 color card fills the entire picture, and then grab the image, which can be clicked to pause playback without guaranteeing accuracy, as shown in the following figure

   

2. The captured image should pay attention to moderate brightness and darkness, and too bright and too dark will affect the calibration

demarcate

Click "Calibration" in the menu bar, select "AWB" to perform calibration, and the program will automatically select the color card

Press any key to continue, popping up the image after white balance is complete

If there is no problem, continue to press any key, the tool will pop up a dialog box asking whether the parameter is reasonable, yes will fill it into the main interface related registers, otherwise abandon the calibration result, if so, the tool will continue to ask whether to write to the device register.

CC

Consistent with AWB calibration, it will not be repeated.

Gamma

The formula for the standard gamma curve is $$ Y=aX^b $$ Where $b$ is the Gamma coefficient, which is generally less than 1 at the imaging end and greater than 1 at the display end. The value of $a$ can be calculated based on the value of $b$

$$ a=\frac{256}{256^b} $$ The principle of the formula is that the input is 256, which is still 256 after Gamma correction.

When the gamma coefficient b is 0.5, the curve is shown in the following figure

LSC

Preparations

• A shot captures a photograph in RAW format

principle

Because the center of the lens is inconsistent with the surrounding light transmission, the image brightness is uneven, so the curve fit generates a corrective surface to compensate for this problem.

The correction is shown in the figure below

After correction, it is shown in the following figure

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