nvJPEG-Decoder

JPEG Image decoding Example using nvJPEG

Description

This code demonstrates JPEG Image decoding utility using nvJPEG library.

Key Concepts

Image Decoding from NVJPEG Library

Supported SM Architectures

SM 3.5 SM 3.7 SM 5.0 SM 5.2 SM 6.0 SM 6.1 SM 7.0 SM 7.2 SM 7.5

Supported OSes

Linux Windows

Supported CPU Architecture

x86_64

CUDA APIs involved

NPP NVJPEG

Architecture

• JPEG decoding is handled by nvJPEG.

Building (make)

Prerequisites

• A Linux/Windows system with recent NVIDIA drivers.
• Install the CUDA 11.0 toolkit [Hardware accelerated decode supported on NVIDIA A100]

Build command on Linux

$ mkdir build
$ cd build
$ cmake ..
$ make

Build command on Windows

$ mkdir build
$ cd build
$ cmake -DCMAKE_GENERATOR_PLATFORM=x64 ..
$ Open imageResize.sln project in Visual Studio 15 2017 and build

Usage

./nvjpegDecoder -h

Usage: ./nvjpegDecoder -i images_dir [-b batch_size] [-t total_images] [-w warmup_iterations] [-o output_dir] [-pipelined] [-batched] [-fmt output_format]
Parameters: 
	images_dir	:	Path to single image or directory of images
	batch_size	:	Decode images from input by batches of specified size
	total_images	:	Decode this much images, if there are less images 
					in the input than total images, decoder will loop over the input
	warmup_iterations	:	Run this amount of batches first without measuring performance
	output_dir	:	Write decoded images as BMPs to this directory
	pipelined	:	Use decoding in phases
	batched		:	Use batched interface
	output_format	:	nvJPEG output format for decoding. One of [rgb, rgbi, bgr, bgri, yuv, y, unchanged]

Example:

Sample example output on GV100, Ubuntu 16.04, CUDA 11.5

$  ./nvjpegDecoder -i ../input_images/ -o ~/tmp

Hardware Decoder not supported. Falling back to default backend
Decoding images in directory: ../input_images/, total 12, batchsize 1
Processing: ../input_images/img3.jpg
Image is 3 channels.
Channel #0 size: 640 x 426
Channel #1 size: 320 x 213
Channel #2 size: 320 x 213
YUV 4:2:0 chroma subsampling
Done writing decoded image to file: /tmp/img3.bmp
Processing: ../input_images/img2.jpg
Image is 3 channels.
Channel #0 size: 480 x 640
Channel #1 size: 240 x 320
Channel #2 size: 240 x 320
YUV 4:2:0 chroma subsampling
Done writing decoded image to file: /tmp/img2.bmp
Processing: ../input_images/img4.jpg
Image is 3 channels.
Channel #0 size: 640 x 426
Channel #1 size: 320 x 213
Channel #2 size: 320 x 213
YUV 4:2:0 chroma subsampling
Done writing decoded image to file: /tmp/img4.bmp
Processing: ../input_images/img5.jpg
Image is 3 channels.
Channel #0 size: 640 x 480
Channel #1 size: 320 x 240
Channel #2 size: 320 x 240
YUV 4:2:0 chroma subsampling
Done writing decoded image to file: /tmp/img5.bmp
Processing: ../input_images/cat_grayscale.jpg
Image is 1 channels.
Channel #0 size: 64 x 64
Grayscale JPEG 
Done writing decoded image to file: /tmp/cat_grayscale.bmp
Processing: ../input_images/cat.jpg
Image is 3 channels.
Channel #0 size: 64 x 64
Channel #1 size: 64 x 64
Channel #2 size: 64 x 64
YUV 4:4:4 chroma subsampling
Done writing decoded image to file: /tmp/cat.bmp
Processing: ../input_images/img9.jpg
Image is 3 channels.
Channel #0 size: 640 x 480
Channel #1 size: 320 x 240
Channel #2 size: 320 x 240
YUV 4:2:0 chroma subsampling
Done writing decoded image to file: /tmp/img9.bmp
Processing: ../input_images/img7.jpg
Image is 3 channels.
Channel #0 size: 480 x 640
Channel #1 size: 240 x 320
Channel #2 size: 240 x 320
YUV 4:2:0 chroma subsampling
Done writing decoded image to file: /tmp/img7.bmp
Processing: ../input_images/img6.jpg
Image is 3 channels.
Channel #0 size: 640 x 480
Channel #1 size: 320 x 240
Channel #2 size: 320 x 240
YUV 4:2:0 chroma subsampling
Done writing decoded image to file: /tmp/img6.bmp
Processing: ../input_images/img1.jpg
Image is 3 channels.
Channel #0 size: 480 x 640
Channel #1 size: 240 x 320
Channel #2 size: 240 x 320
YUV 4:2:0 chroma subsampling
Done writing decoded image to file: /tmp/img1.bmp
Processing: ../input_images/cat_baseline.jpg
Image is 3 channels.
Channel #0 size: 64 x 64
Channel #1 size: 64 x 64
Channel #2 size: 64 x 64
YUV 4:4:4 chroma subsampling
Done writing decoded image to file: /tmp/cat_baseline.bmp
Processing: ../input_images/img8.jpg
Image is 3 channels.
Channel #0 size: 480 x 640
Channel #1 size: 240 x 320
Channel #2 size: 240 x 320
YUV 4:2:0 chroma subsampling
Done writing decoded image to file: /tmp/img8.bmp
Total decoding time: 0.0135301 (s)
Avg decoding time per image: 0.00112751 (s)
Avg images per sec: 886.911
Avg decoding time per batch: 0.00112751 (s)