dji-thermal-sdk 1.3.20220517

use ctypes to invoke the DJI thermal SDK to process images.

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')
'''