DJI Thermal SDK

use ctypes to capsulate the DJI Thermal SDK so that we can directly use python to process thermal images.

import nbdev
from dji_thermal_sdk.dji_sdk import *
import dji_thermal_sdk.dji_sdk as DJI
import ctypes as CT
from ctypes import *
import os

This version of DJI Thermal SDK is 1.3, which was published on 05/15/2022

Install

pip install dji_thermal_sdk

Load DLL

Normally, DJI SDK DLLs include libdirp.dll, libv_dirp.dll, libv_girp.dll, libv_iirp.dll, libv_list.ini.

you should put all the dlls and your codes in a same folder.

The reason that the following codes are commented is because it can't pass the GitHub CI test, but it works well.

DJI dlls use C++, and when we use ctypes to invoke them, python complier will pop out 'invalid ELF header' error.

'''
try:
    _libdirp = cdll.LoadLibrary("./libdirp.dll")
    DJI.set_dirp_dll(_libdirp)
except FileNotFoundError as err:
    print(err)
print(DJI._libdirp)
'''

<CDLL 'D:\LYU\Code\git_repository\dji_thermal_sdk\libdirp.dll', handle 7ffe6f310000 at 0x1aa05b61850>





True

Get the handle of a R-JPEG image

DIRP_HANDLE is a void pointer, and it has been definded.
you can get it by package.DIRP_HANDLE

nbdev.show_doc(dirp_create_from_rjpeg)

dirp_create_from_rjpeg[source]

dirp_create_from_rjpeg(data, size, ph)

Parameters: [in] data: R-JPEG binary data buffer pointer [in] size: R-JPEG binary data buffer size in bytes [out]ph : DIRP API handle pointer - reminder: use two-level pointer to assign value to one-level pointer Return: int return code dirp_ret_code_e

'''
rd = r"dataset\Deer_Goats_Unsure__2022-02-02__02-42-12(2).JPG"
with open(rd, 'rb') as f:
    content = f.read()
    print(len(content))
# method1 to get the file size
print(f"File size: {os.path.getsize(rd)}")
# method 2 to get the file size
file_stat = os.stat(rd)
size = c_int32(file_stat.st_size)
print(f"File size: {size}")

# the method to create a string buffer, which is important.
rjpeg_data = CT.create_string_buffer(len(content))
rjpeg_data.value = content
print(f"rjpeg_data: {rjpeg_data}")

# test the function to create a handle of an image
ret = dirp_create_from_rjpeg(rjpeg_data,size, CT.byref(DIRP_HANDLE))
print(f'ret = {ret}')
if ret == 0:
    print("successfully get the r-jpeg handle.")
#
print(f"DIRP_HANDLE: {DIRP_HANDLE}  address: {hex(DIRP_HANDLE.value)} ")
'''

Get the version of API

nbdev.show_doc(dirp_get_api_version)

dirp_get_api_version[source]

dirp_get_api_version(version)

Parameters: [out] version DIRP API version information pointer Return: int return code dirp_ret_code_e

nbdev.show_doc(dirp_api_version_t)

class dirp_api_version_t[source]

dirp_api_version_t() :: Structure

API version structure definition

'''
jpeg_version = dirp_api_version_t() 
ret = dirp_get_api_version(CT.byref(jpeg_version))
if ret == DIRP_SUCCESS:
    print("Success")
#
print(f"jpeg_version.api: \t {jpeg_version.api}")
print(f"jpeg_version.magic: \t {jpeg_version.magic}")
'''

Get Color Bar

nbdev.show_doc(dirp_get_color_bar)

dirp_get_color_bar[source]

dirp_get_color_bar(h, color_bar)

Parameters: [in] h: DIRP API handle [out] color_bar: ISP color bar parameters pointer Return: int return code dirp_ret_code_e

nbdev.show_doc(dirp_color_bar_t)

class dirp_color_bar_t[source]

dirp_color_bar_t() :: Structure

Color bar parameters structure definition

'''
jpeg_color_bar = dirp_color_bar_t()
ret = dirp_get_color_bar(DIRP_HANDLE, CT.byref(jpeg_color_bar))
if ret == DIRP_SUCCESS:
    print("Success")
print(f"jpeg_color_bar.high: \t {jpeg_color_bar.high}")
print(f"jpeg_color_bar.low: \t {jpeg_color_bar.low}")
print(f"jpeg_color_bar.manual_enable: \t {jpeg_color_bar.manual_enable}")
'''

Get the resolution of a R-JPEG image

nbdev.show_doc(dirp_create_from_rjpeg)

nbdev.show_doc(dirp_get_rjpeg_resolution)

dirp_get_rjpeg_resolution[source]

dirp_get_rjpeg_resolution(h, rjpeg_info)

Get R-JPEG image resolution information. Parameters [in]h: DIRP API handle [out]rjpeg_info: R-JPEG basic information pointer Returns int return code dirp_ret_code_e

nbdev.show_doc(dirp_resolution_t)

class dirp_resolution_t[source]

dirp_resolution_t() :: Structure

The image size structure definition

'''
rjpeg_resolution = dirp_resolution_t()
ret = dirp_get_rjpeg_resolution(DIRP_HANDLE, CT.byref(rjpeg_resolution))
print(f'ret = {ret}')
if ret == 0:
    print("successfully get the resolution.")

out = f'Height: {rjpeg_resolution.height}, width: {rjpeg_resolution.width}'
out
'''

Set Pseudo Color

nbdev.show_doc(dirp_set_pseudo_color)

'''
ret = dirp_set_pseudo_color(DIRP_HANDLE, c_int(0))
if ret == DIRP_SUCCESS:
    print("Success")
else:
    print(f"Error: ret={ret}")
'''

Transform a thermal image by a specific palette

nbdev.show_doc(dirp_process)

'''
import matplotlib.pyplot as plt
import numpy as np
size = rjpeg_resolution.height * rjpeg_resolution.width * 3 * CT.sizeof(c_uint8)
raw_image_buffer = CT.create_string_buffer(size)
print(raw_image_buffer.raw[100])
ret = dirp_process(DIRP_HANDLE,byref(raw_image_buffer), size)
if ret == DIRP_SUCCESS:
    print("Success")
else:
    print(f"Error: ret={ret}")
#
raw_file_path = os.path.splitext(rd)[0] + ".raw"
print(raw_file_path)
with open(raw_file_path, 'wb') as f:
    f.write(raw_image_buffer.raw)
#
if os.path.exists(raw_file_path):
    print(f"Success! file size: {os.path.getsize(raw_file_path)}")
else:
    print("Error")
#
with open(raw_file_path, encoding='cp1252') as fin:
    img = np.fromfile(fin, dtype = np.uint8)
    print(img.shape)
    img.shape = (512,640,3)
    #original = Image.fromarray(img)
#

fig = plt.figure(figsize=(10,8))
plt.imshow(img, cmap='gray')
'''