The APIs under this category are used to initialize the decoding parameters as part of the nvtiffDecodeParams_t handle. Once initialized, the handle can be passed as an input to nvtiffDecodeImage()

nvtiffDecodeParamsSetOutputFormat()

Used to set the decode output format. See Decode Output Format for details. The default value is NVTIFF_OUTPUT_UNCHANGED_I.

Note

When the photometric interpretation is NVTIFF_PHOTOMETRIC_YCBCR and compression is NVTIFF_COMPRESSION_JPEG, output format must be set to either NVTIFF_OUTPUT_RGB_I_UINT8 or NVTIFF_OUTPUT_RGB_I_UINT16.

Note

When the photometric interpretation is NVTIFF_PHOTOMETRIC_MASK, only NVTIFF_OUTPUT_UNCHANGED_I can be used.

When setting the output format to NVTIFF_OUTPUT_UNCHANGED_I-

the size in bytes of the decode output buffer when bits_per_pixel is a multiple 8, should be image_width * image_height * (bits_per_pixel/8). If using _nvtiffdecodeimageex-label, the pitch must be at least image_width * (bits_per_pixel/8) and aligned to bits_per_sample[0]/8.

the size in bytes of the decode output buffer when bits_per_pixel is less than 8, should be (image_width * bits_per_pixel + 7)/8  * image_height. If using _nvtiffdecodeimageex-label, the pitch must be at least (image_width * bits_per_pixel + 7)/8) and aligned to bits_per_sample[0]/8.

When setting the output to NVTIFF_OUTPUT_RGB_I_UINT8-

the size in bytes of the decode output buffer should be image_width * image_height * 3 * sizeof(uint8_t). If using _nvtiffdecodeimageex-label, the pitch must be at least image_width * 3 * sizeof(uint8_t).

When setting the output to NVTIFF_OUTPUT_RGB_I_UINT16-

the size in bytes of the decode output buffer should be image_width * image_height * 3 * sizeof(uint16_t). If using _nvtiffdecodeimageex-label, the pitch must be at least image_width * 3 * sizeof(uint8_t), and aligned to sizeof(uint16_t).

Signature:

nvtiffStatus_t nvtiffDecodeParamsSetOutputFormat(nvtiffDecodeParams_t decode_params,
    nvtiffOutputFormat_t format);

Parameters:

Parameter	Input/Output	Memory	Description
nvtiffDecodeParams_t decode_params	Input/Output	Host	Decode output parameters handle.
nvtiffOutputFormat_t format	Input	Host	Output format value. Defaults to NVTIFF_OUTPUT_UNCHANGED_I.

Returns:

nvtiffStatus_t - An error code as specified in Decode API Return Status Codes

nvtiffDecodeParamsSetROI()

Used to set the region of interest for decoding. The entire image is decoded by default.

• offset_x and offset_y should be greater than or equal to 0, and cannot exceed image width and height respectively.

• offset_x + roi_width and offset_y + roi_height cannot exceed image width and image height respectively.

• When image bitdepth is 1, offset_x and roi_width should be a multiple of 8

Signature:

nvtiffStatus_t nvtiffDecodeParamsSetROI(nvtiffDecodeParams_t decode_params,
        int32_t offset_x,
        int32_t offset_y,
        int32_t roi_width,
        int32_t roi_height)

Parameters:

Parameter	Input/Output	Memory	Description
nvtiffDecodeParams_t decode_params	Input/Output	Host	Decode output parameter handle
int32_t offset_x	Input	Host	Image offset along the horizontal direction relative to the top left corner.
int32_t offset_y	Input	Host	Image offset along the vertical direction relative to the top left corner.
int32_t roi_width	Input	Host	Image width relative to offset_x
int32_t roi_height	Input	Host	Image height relative to offset_y

Returns:

nvtiffStatus_t - An error code as specified in Decode API Return Status Codes