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Defect Pixel Correction#

Defect Pixel Correction 相机功能允许您将传感器各个像素的灵敏度差异的影响降至最低。

在采集的图像中，即使使用均匀的光线，部分像素也会显得比其他像素明显更亮或更暗。该问题是由于各个像素的灵敏度差异而引起的，而这些差异又是由于生产公差引起的。

该功能的使用#

The implementation of this feature varies by camera series:

ace 2 R/X and boost R Cameras#

Basler ace 2 R, ace 2 X, and boost R cameras support static defect pixel correction. This correction is based on files that are stored on the camera and contain a list of defect pixel coordinates.

“静态”意味着始终使用相同的指定缺陷像素坐标执行校正过程。在图像采集期间，这些像素的强度值将根据其相邻像素的强度值进行替换。

以下 Defect Pixel Correction 文件可以存储在相机上：

  • 工厂文件：包含相机生产过程中检测到的缺陷像素的坐标。
  • 用户文件：包含用户定义的坐标。您可以将此文件上传到相机。这允许您定义随着时间的推移可能出现的新缺陷像素。

信息

Basler ace 2 X cameras also support dynamic pixel defect correction. For more information, see Pixel Correction Beyond.

使用 pylon Viewer 校正缺陷像素#

→ 请参阅静态 Defect Pixel Correction (pylon Viewer)。

使用 pylon API 校正缺陷像素#

信息

Basler 建议使用 pylon Viewer 执行 Defect Pixel Correction。

仅当您想要在自己的应用中实现 Defect Pixel Correction 时，才使用 pylon API。

设置静态 Defect Pixel Correction 模式#

To set the static defect pixel correction mode, set the BslStaticDefectPixelCorrectionMode parameter to one of the following values:

  • Factory (default): Static defect pixel correction is based on the defect pixels stored in the factory correction file.
  • User: Static defect pixel correction is based on the defect pixels stored in the user correction file.
    Note that when setting this mode via the pylon API, only the user-defined pixels will be used. When setting the User incl. Factory correction mode via the pylon Viewer, user-defined pixels will be used in addition to the pixels stored in the factory file.
  • Off: The camera does not perform static defect pixel corrections.
上传用户 Defect Pixel Correction 文件#

在上传用户 Defect Pixel Correction 文件之前，请确保该文件符合以下文件格式：

文件必须以包含四个值为 0 的字节的 4 字节标题开头。在标题之后，文件必须包含缺陷像素条目（最多可以指定 4096 个缺陷像素）。每个条目由 32 位组成，顺序如下：14 位 y 坐标、14 位 x 坐标、4 位类型

示例：坐标为 x=1 和 y=2 的缺陷像素条目

Bit   |31          18| |17           4| |3  0|
Value |00000000000010| |00000000000001| |0000|
      | y = 2        | | X = 1        | |type|

使用 pylon Viewer 上传用户 Defect Pixel Correction 文件：

  1. 在 pylon Viewer 的相机菜单中，单击文件访问权限。
  2. 在相机文件下拉框中，选择用户 Defect Pixel Correction。
    如果没有用户 Defect Pixel Correction 条目，您的相机不支持上传校正文件。
  3. 单击上传并导航到要上传的文件。
  4. 单击打开。

To apply the user defect pixel correction file after uploading, make sure that the BslStaticDefectPixelCorrectionMode parameter is set to User and execute the BslStaticDefectPixelCorrectionReload command.

下载 Defect Pixel Correction 文件#

如果您想要将自己测量的缺陷像素添加到下载的文件中，下载 Defect Pixel Correction 文件（例如出厂校正文件）可能会很有用。您可以将缺陷像素条目的完整列表存储在新的用户校正文件中。

使用 pylon Viewer 下载 Defect Pixel Correction 文件：

  1. 在 pylon Viewer 的相机菜单中，单击文件访问权限。
  2. 在相机文件下拉框中，根据您要下载的文件，选择静态出厂 Defect Pixel Correction 或静态用户 Defect Pixel Correction。
    如果没有适当的条目，则您的相机不支持下载文件。
  3. 单击下载，导航到要保存文件的目录，然后输入所需的文件名。
  4. 单击打开。
静态 Defect Pixel Correction 文件状态#

The StaticDefectPixelCorrectionFileStatus parameter can take the following values:

  • FileStatusUnknown: The status of the defect pixel correction file is unknown. Acquire an image to change the file status.
  • FileOk: The defect pixel correction file is valid.
  • FileNotFound: The defect pixel correction file can't be found. It has never been uploaded or was deleted.
  • FileEmpty: The defect pixel correction file has no entries. The file header is valid but the file doesn't contain any defect pixels. The defect pixel correction process is aborted.
  • InvalidHeader: The defect pixel correction file header is invalid. The file must have a 4-byte file header.
  • InvalidSize: The defect pixel correction file size is invalid. The maximum number of defective pixels must not exceed 4096.
  • InvalidSorting: The sorting of entries in the defect pixel correction file is invalid. The defect pixel correction process is aborted.
  • InvalidFileEntry: At least one entry in the defect pixel correction file has an invalid size. The defect pixel correction process is aborted.
  • InvalidClustering: An invalid cluster has been found. Three or more adjacent pixels in a row are considered an invalid cluster. Any defect pixels between other defect pixels can't be corrected.

The defect pixel correction file can contain a maximum number of defect pixels. To get the number, get the value of the BslStaticDefectPixelCorrectionMaxDefects parameter.

boost V 相机#

Basler boost V 相机支持静态 Defect Pixel Correction。此校正基于存储在相机上并包含缺陷像素坐标列表的文件。

“静态”意味着始终使用相同的指定缺陷像素坐标执行校正过程。在图像采集期间，这些像素的强度值将根据其相邻像素的强度值进行替换。

执行 Defect Pixel Correction#

信息

pylon Viewer 的内置静态 Defect Pixel Correction 功能不支持 boost V 相机。

使用 pylon Viewer 或 pylon API 的特征树对 boost V 相机进行 Defect Pixel Correction。

要对 boost V 相机执行 Defect Pixel Correction：

  1. Set the BslStaticDefectPixelCorrectionMode parameter to the desired correction mode:

    • Factory: Only defect pixels whose coordinates are stored in the factory file are corrected. The factory file is generated during camera production and can't be changed.
    • User: You can specify custom defect pixel coordinates.
    • Off: The camera does not perform static defect pixel corrections.

  2. If you selected User:

    1. 找出图像中的像素错误，并记下缺陷像素的 x 和 y 坐标。
    2. Set the BslStaticDefectPixelCorrectionYCoordinate parameter to the y coordinate of the first defect pixel.
    3. Set the BslStaticDefectPixelCorrectionXSelector parameter to X0.
    4. Set the BslStaticDefectPixelCorrectionXCoordinate parameter to the x coordinate of the first defect pixel.
    5. If there's another defect pixel with the same y coordinate, but a different x coordinate, set the BslStaticDefectPixelCorrectionXSelector parameter to the next entry, e.g., X1, and enter the next x coordinate.
    6. 对所有其他像素错误重复步骤 b。
    7. Execute the BslStaticDefectPixelCorrectionSave command to save changes to flash memory.

信息

  • You can use the BslStaticDefectPixelCorrectionCount parameter to check how many image pixels are currently being corrected.
  • You can set the BslStaticDefectPixelCorrectionTestMode parameter to On to set all corrected pixels to completely white. This helps to find pixels that are being corrected in your images.

删除缺陷像素坐标#

不能删除出厂文件中的像素坐标。

但是，您可以删除自定义缺陷像素坐标，即在“用户”校正模式下输入的坐标（请参阅上文）。为此：

  • 如果要移除单个自定义缺陷像素坐标：

    1. Set the BslStaticDefectPixelCorrectionYCoordinate parameter to the y coordinate of the defect pixel.
    2. Set the BslStaticDefectPixelCorrectionXSelector parameter to the entry that holds the x coordinate of the defect pixel, e.g., X0.
    3. Set the BslStaticDefectPixelCorrectionXCoordinate parameter to 0xFFFF.
    4. Execute the BslStaticDefectPixelCorrectionSave command to save changes to flash memory.

  • 如果要移除所有自定义缺陷像素坐标：

    1. Execute the BslStaticDefectPixelCorrectionClearAll command. This sets all BslStaticDefectPixelCorrectionXCoordinate parameter values to 0xFFFF.
    2. Execute the BslStaticDefectPixelCorrectionSave command to save changes to flash memory.

dart 和 pulse 相机#

Basler dart 和 pulse 相机可以执行两种类型的像素校正：

  • The static pixel correction corrects pixels that have significantly lesser intensity values than their neighboring pixels, including completely black pixels.
  • The dynamic pixel correction corrects pixels that have significantly higher intensity values than their neighboring pixels, including completely white pixels. An internal threshold value defines when a pixel is detected as a "hot pixel". "Dynamic" means that the defect pixel correction is calculated individually for each acquired image.

设置 Defect Pixel Correction 模式#

To set the defect pixel correction mode, set the BslDefectPixelCorrectionMode parameter to one of the following values:

  • On (default): The camera performs static and dynamic pixel corrections.
  • StaticOnly: The camera performs the static pixel correction only.
  • Off: The camera does not perform pixel corrections.

示例代码#

ace 2 R/X and boost R Cameras#
// Set static user defect pixel correction
camera.BslStaticDefectPixelCorrectionMode.SetValue(BslStaticDefectPixelCorrectionMode_User);
// Reload static defect pixel correction file
camera.BslStaticDefectPixelCorrectionReload.Execute();

INodeMap& nodemap = camera.GetNodeMap();
// Set static user defect pixel correction
CEnumParameter(nodemap, "BslStaticDefectPixelCorrectionMode").SetValue("User");
// Reload static defect pixel correction file
CCommandParameter(nodemap, "BslStaticDefectPixelCorrectionReload").Execute();

// Set static user defect pixel correction
camera.Parameters[PLCamera.BslStaticDefectPixelCorrectionMode].SetValue(PLCamera.BslStaticDefectPixelCorrectionMode.User);
// Reload static defect pixel correction file
camera.Parameters[PLCamera.BslStaticDefectPixelCorrectionReload].Execute();

/* Macro to check for errors */
#define CHECK(errc) if (GENAPI_E_OK != errc) printErrorAndExit(errc)
GENAPIC_RESULT errRes = GENAPI_E_OK;  /* Return value of pylon methods */
/* Set static user defect pixel correction */
errRes = PylonDeviceFeatureFromString(hdev, "BslStaticDefectPixelCorrectionMode", "User");
CHECK(errRes);
/* Reload static defect pixel correction file */
errRes = PylonDeviceExecuteCommandFeature(hdev, "BslStaticDefectPixelCorrectionReload");
CHECK(errRes);

# Set static user defect pixel correction
camera.BslStaticDefectPixelCorrectionMode.Value = "User"
# Reload static defect pixel correction file
camera.BslStaticDefectPixelCorrectionReload.Execute()
boost V 相机#
// Set the defect pixel correction mode to User
camera.BslStaticDefectPixelCorrectionMode.SetValue(BslStaticDefectPixelCorrectionMode_User);
// Assume there are two defect pixels at coordinates (120,430) and (182,430)
// Set the y coordinate to 430
camera.BslStaticDefectPixelCorrectionYCoordinate.SetValue(430);
// Select entry X0 and assign the first x coordinate
camera.BslStaticDefectPixelCorrectionXSelector.SetValue(BslStaticDefectPixelCorrectionXSelector_X0);
camera.BslStaticDefectPixelCorrectionXCoordinate.SetValue(120);
// Select entry X1 and assign the second x coordinate, which is in the same line
camera.BslStaticDefectPixelCorrectionXSelector.SetValue(BslStaticDefectPixelCorrectionXSelector_X1);
camera.BslStaticDefectPixelCorrectionXCoordinate.SetValue(182);
// Save changes to flash memory
camera.BslStaticDefectPixelCorrectionSave.Execute();

INodeMap& nodemap = camera.GetNodeMap();
// Set the defect pixel correction mode to User
CEnumParameter(nodemap, "BslStaticDefectPixelCorrectionMode").SetValue("User");
// Assume there are two defect pixels at coordinates (120,430) and (182,430)
// Set the y coordinate to 430
CIntegerParameter(nodemap, "BslStaticDefectPixelCorrectionYCoordinate").SetValue(430);
// Select entry X0 and assign the first x coordinate
CEnumParameter(nodemap, "BslStaticDefectPixelCorrectionXSelector").SetValue("X0");
CIntegerParameter(nodemap, "BslStaticDefectPixelCorrectionXCoordinate").SetValue(120);
// Select entry X1 and assign the second x coordinate, which is in the same line
CEnumParameter(nodemap, "BslStaticDefectPixelCorrectionXSelector").SetValue("X1");
CIntegerParameter(nodemap, "BslStaticDefectPixelCorrectionXCoordinate").SetValue(182);
// Save changes to flash memory
CCommandParameter(nodemap, "BslStaticDefectPixelCorrectionSave").Execute();

// Set the defect pixel correction mode to User
camera.Parameters[PLCamera.BslStaticDefectPixelCorrectionMode].SetValue(PLCamera.BslStaticDefectPixelCorrectionMode.User);
// Assume there are two defect pixels at coordinates (120,430) and (182,430)
// Set the y coordinate to 430
camera.Parameters[PLCamera.BslStaticDefectPixelCorrectionYCoordinate].SetValue(430);
// Select entry X0 and assign the first x coordinate
camera.Parameters[PLCamera.BslStaticDefectPixelCorrectionXSelector].SetValue(PLCamera.BslStaticDefectPixelCorrectionXSelector.X0);
camera.Parameters[PLCamera.BslStaticDefectPixelCorrectionXCoordinate].SetValue(120);
// Select entry X1 and assign the second x coordinate, which is in the same line
camera.Parameters[PLCamera.BslStaticDefectPixelCorrectionXSelector].SetValue(PLCamera.BslStaticDefectPixelCorrectionXSelector.X1);
camera.Parameters[PLCamera.BslStaticDefectPixelCorrectionXCoordinate].SetValue(182);
// Save changes to flash memory
camera.Parameters[PLCamera.BslStaticDefectPixelCorrectionSave].Execute();

/* Macro to check for errors */
#define CHECK(errc) if (GENAPI_E_OK != errc) printErrorAndExit(errc)
GENAPIC_RESULT errRes = GENAPI_E_OK;  /* Return value of pylon methods */
/* Set the defect pixel correction mode to User */
errRes = PylonDeviceFeatureFromString(hdev, "BslStaticDefectPixelCorrectionMode", "User");
CHECK(errRes);
/* Assume there are two defect pixels at coordinates (120,430) and (182,430) */
/* Set the y coordinate to 430 */
errRes = PylonDeviceSetIntegerFeature(hdev, "BslStaticDefectPixelCorrectionYCoordinate", 430);
CHECK(errRes);
/* Select entry X0 and assign the first x coordinate */
errRes = PylonDeviceFeatureFromString(hdev, "BslStaticDefectPixelCorrectionXSelector", "X0");
CHECK(errRes);
errRes = PylonDeviceSetIntegerFeature(hdev, "BslStaticDefectPixelCorrectionXCoordinate", 120);
CHECK(errRes);
/* Select entry X1 and assign the second x coordinate, which is in the same line */
errRes = PylonDeviceFeatureFromString(hdev, "BslStaticDefectPixelCorrectionXSelector", "X1");
CHECK(errRes);
errRes = PylonDeviceSetIntegerFeature(hdev, "BslStaticDefectPixelCorrectionXCoordinate", 182);
CHECK(errRes);
/* Save changes to flash memory */
errRes = PylonDeviceExecuteCommandFeature(hdev, "BslStaticDefectPixelCorrectionSave");
CHECK(errRes);

# Set the defect pixel correction mode to User
camera.BslStaticDefectPixelCorrectionMode.Value = "User"
# Assume there are two defect pixels at coordinates (120,430) and (182,430)
# Set the y coordinate to 430
camera.BslStaticDefectPixelCorrectionYCoordinate.Value = 430
# Select entry X0 and assign the first x coordinate
camera.BslStaticDefectPixelCorrectionXSelector.Value = "X0"
camera.BslStaticDefectPixelCorrectionXCoordinate.Value = 120
# Select entry X1 and assign the second x coordinate, which is in the same line
camera.BslStaticDefectPixelCorrectionXSelector.Value = "X1"
camera.BslStaticDefectPixelCorrectionXCoordinate.Value = 182
# Save changes to flash memory
camera.BslStaticDefectPixelCorrectionSave.Execute()
dart 和 pulse 相机#
// Disable defect pixel correction
camera.BslDefectPixelCorrectionMode.SetValue(BslDefectPixelCorrectionMode_Off);

INodeMap& nodemap = camera.GetNodeMap();
// Disable defect pixel correction
CEnumParameter(nodemap, "BslDefectPixelCorrectionMode").SetValue("Off");

// Disable defect pixel correction
camera.Parameters[PLCamera.BslDefectPixelCorrectionMode].SetValue(PLCamera.BslDefectPixelCorrectionMode.Off);

/* Macro to check for errors */
#define CHECK(errc) if (GENAPI_E_OK != errc) printErrorAndExit(errc)
GENAPIC_RESULT errRes = GENAPI_E_OK;  /* Return value of pylon methods */
/* Disable defect pixel correction */
errRes = PylonDeviceFeatureFromString(hdev, "BslDefectPixelCorrectionMode", "Off");
CHECK(errRes);

# Disable defect pixel correction
camera.BslDefectPixelCorrectionMode.Value = "Off"

您也可以使用 pylon Viewer 轻松设置参数。