Function af_save_image_memory

src/api/c/imageio.cpp:860–1037

Save an image to memory.

// Save an image to memory.
af_err af_save_image_memory(void** ptr, const af_array in_,
                            const af_image_format format) {
    try {
        FreeImage_Module& _ = getFreeImagePlugin();

        // set our own FreeImage error handler
        _.FreeImage_SetOutputMessage(FreeImageErrorHandler);

        // try to guess the file format from the file extension
        auto fif = static_cast<FREE_IMAGE_FORMAT>(format);

        if (fif == FIF_UNKNOWN || fif > 34) {  // FreeImage FREE_IMAGE_FORMAT
                                               // has upto 34 enums as of 3.17
            AF_ERROR("FreeImage Error: Unknown Filetype", AF_ERR_NOT_SUPPORTED);
        }

        const ArrayInfo& info = getInfo(in_);
        // check image color type
        uint channels = info.dims()[2];
        DIM_ASSERT(1, channels <= 4);
        DIM_ASSERT(1, channels != 2);

        uint fi_bpp = channels * 8;

        // sizes
        uint fi_w = info.dims()[1];
        uint fi_h = info.dims()[0];

        // create the result image storage using FreeImage
        bitmap_ptr pResultBitmap = make_bitmap_ptr(_.FreeImage_Allocate(
            fi_w, fi_h, static_cast<int>(fi_bpp), 0, 0, 0));
        if (pResultBitmap == NULL) {
            AF_ERROR("FreeImage Error: Error creating image or file",
                     AF_ERR_RUNTIME);
        }

        // FI assumes [0-255]
        // If array is in 0-1 range, multiply by 255
        af_array in;
        double max_real, max_imag;
        bool free_in = false;
        AF_CHECK(af_max_all(&max_real, &max_imag, in_));
        if (max_real <= 1) {
            af_array c255;
            AF_CHECK(af_constant(&c255, 255.0, info.ndims(), info.dims().get(),
                                 f32));
            AF_CHECK(af_mul(&in, in_, c255, false));
            AF_CHECK(af_release_array(c255));
            free_in = true;
        } else {
            in = in_;
        }

        // FI = row major | AF = column major
        uint nDstPitch = _.FreeImage_GetPitch(pResultBitmap.get());
        uchar* pDstLine =
            _.FreeImage_GetBits(pResultBitmap.get()) + nDstPitch * (fi_h - 1);
        af_array rr = 0, gg = 0, bb = 0, aa = 0;