Using Image_NativeModule for PixelMap Operations

You can use the Pixelmap class to create, operation and release a PixelMap, and obtain its width, height, pixel format, alpha type, and row stride.

How to Develop

Adding a Link Library

Open the src/main/cpp/CMakeLists.txt file of the native project, add libpixelmap.so and libhilog_ndk.z.so (on which the log APIs depend) to the target_link_libraries dependency.

target_link_libraries(entry PUBLIC libhilog_ndk.z.so libpixelmap.so)

Calling the Native APIs

For details about the APIs, see Image_NativeModule.

Implement the C APIs in hello.cpp. Refer to the sample code below.

Example of Using the Pixelmap APIs

Create a Pixelmap instance after parameter initialization, read and write pixel data, and perform operations such as scaling, translating, flipping, rotating, and cropping on the image.

   #include <linux/kd.h>
   #include <string>

   #include <hilog/log.h>
   #include <multimedia/image_framework/image/pixelmap_native.h>

   #undef LOG_DOMAIN
   #undef LOG_TAG
   #define LOG_DOMAIN 0x3200
   #define LOG_TAG "MY_TAG"

   Image_ErrorCode PixelmapTest()
   {
       uint8_t data[96];
       size_t dataSize = 96;
       for (int i = 0; i < dataSize; i++) {
           data[i] = i + 1;
       }

       // Create a parameter structure instance and set parameters.
       OH_Pixelmap_InitializationOptions *createOpts;
       OH_PixelmapInitializationOptions_Create(&createOpts);
       OH_PixelmapInitializationOptions_SetWidth(createOpts, 6);
       OH_PixelmapInitializationOptions_SetHeight(createOpts, 4);
       OH_PixelmapInitializationOptions_SetPixelFormat(createOpts, PIXEL_FORMAT_RGBA_8888);
       OH_PixelmapInitializationOptions_SetAlphaType(createOpts, PIXELMAP_ALPHA_TYPE_UNKNOWN);

       // Create a Pixelmap instance.
       OH_PixelmapNative *pixelmap = nullptr;
       Image_ErrorCode errCode = OH_PixelmapNative_CreatePixelmap(data, dataSize, createOpts, &pixelmap);

       // Read the image pixel data and write the data to the array.
       uint8_t destination[96];
       size_t destinationSize = 96;
       errCode = OH_PixelmapNative_ReadPixels(pixelmap, destination, &destinationSize);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImagePixelmapNativeCTest pixelmapTest OH_PixelmapNative_ReadPixels failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Read the image data in the buffer and write the data to the Pixelmap instance.
       uint8_t source[96];
       size_t sourceSize = 96;
       for (int i = 0; i < sourceSize; i++) {
           source[i] = i + 1;
       }
       errCode = OH_PixelmapNative_WritePixels(pixelmap, source, sourceSize);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImagePixelmapNativeCTest pixelmapTest OH_PixelmapNative_WritePixels failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Create an image information instance and obtain the pixel information.
       OH_Pixelmap_ImageInfo *imageInfo;
       OH_PixelmapImageInfo_Create(&imageInfo);
       errCode = OH_PixelmapNative_GetImageInfo(pixelmap, imageInfo);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImagePixelmapNativeCTest pixelmapTest OH_PixelmapNative_GetImageInfo failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Obtain the width, height, pixel format, and alpha type of the image.
       uint32_t width, height, rowStride;
       int32_t pixelFormat, alphaType;
       OH_PixelmapImageInfo_GetWidth(imageInfo, &width);
       OH_PixelmapImageInfo_GetHeight(imageInfo, &height);
       OH_PixelmapImageInfo_GetRowStride(imageInfo, &rowStride);
       OH_PixelmapImageInfo_GetPixelFormat(imageInfo, &pixelFormat);
       OH_PixelmapImageInfo_GetAlphaType(imageInfo, &alphaType);
       OH_PixelmapImageInfo_Release(imageInfo);
       OH_LOG_INFO(LOG_APP, "ImagePixelmapNativeCTest pixelmapTest GetImageInfo success, width: %{public}d, height: %{public}d, rowStride: %{public}d, pixelFormat: %{public}d, alphaType: %{public}d.", width, height, rowStride, pixelFormat, alphaType);

       // Set the opacity rate to enable the image to achieve the corresponding opacity effect.
       errCode = OH_PixelmapNative_Opacity(pixelmap, 0.5);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImagePixelmapNativeCTest pixelmapTest OH_PixelmapNative_Opacity failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Scale the image.
       errCode = OH_PixelmapNative_Scale(pixelmap, 2.0, 1.0);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImagePixelmapNativeCTest pixelmapTest OH_PixelmapNative_Scale failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Translate the image.
       errCode = OH_PixelmapNative_Translate(pixelmap, 50.0, 10.0);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImagePixelmapNativeCTest pixelmapTest OH_PixelmapNative_Translate failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Rotate the image.
       errCode = OH_PixelmapNative_Rotate(pixelmap, 90.0);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImagePixelmapNativeCTest pixelmapTest OH_PixelmapNative_Rotate failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Flip the image.
       errCode = OH_PixelmapNative_Flip(pixelmap, true, true);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImagePixelmapNativeCTest pixelmapTest OH_PixelmapNative_Flip failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Crop the image.
       Image_Region region;
       region.x = 100;
       region.y = 100;
       region.width = 6;
       region.height = 4;
       errCode = OH_PixelmapNative_Crop(pixelmap, &region);
       if (errCode != IMAGE_SUCCESS) {
           OH_LOG_ERROR(LOG_APP, "ImagePixelmapNativeCTest pixelmapTest OH_PixelmapNative_Crop failed, errCode: %{public}d.", errCode);
           return errCode;
       }

       // Release the Pixelmap and InitializationOptions instances.
       OH_PixelmapNative_Release(pixelmap);
       OH_PixelmapInitializationOptions_Release(createOpts);
       return IMAGE_SUCCESS;
   }