Contour/Elevations inverted

Hi, I’m pretty new to mapping and I’m a bit confused by the output I’m getting on my first project. Any guidance would be appreciated - It’s not absolutely critical that I fix this today, but if there’s an error in my process I’d like to learn about it now and deal with it.

The input files were a set of 54 pictures taken with a Mavic Mini, with the camera pointing straight down. I flew the path by hand and I wasn’t expecting great results but I was actually delighted with the 3d model that was produced, and with most of the outputs.

The issue I’m having is that the elevation seems to be somehow inverted on the DTM. The actual contour lines etc seem sensible, but what’s being identified as the highest point is actually the lowest, and vice versa.

Here’s the model - the reddish area in the top right is almost certainly the highest area, and the grey border on the bottom left is the lowest:

image

Using Windows 10, Chrome, manual install of WebODM, didn’t change much other than adding the dtm to the output.

Console output (truncated since it’s too long, let me know if anything critical missing):

[INFO] Initializing ODM - Sat Mar 21 09:04:32 2020
[INFO] ==============
[INFO] build_overviews: False
[INFO] camera_lens: auto
[INFO] cameras: {}
[INFO] crop: 3
[INFO] debug: False
[INFO] dem_decimation: 1
[INFO] dem_euclidean_map: False
[INFO] dem_gapfill_steps: 3
[INFO] dem_resolution: 5
[INFO] depthmap_resolution: 640
[INFO] dsm: True
[INFO] dtm: True
[INFO] end_with: odm_orthophoto
[INFO] fast_orthophoto: False
[INFO] feature_type: sift
[INFO] force_gps: False
[INFO] gcp: None
[INFO] ignore_gsd: False
[INFO] matcher_distance: 0
[INFO] matcher_neighbors: 8
[INFO] max_concurrency: 4
[INFO] merge: all
[INFO] mesh_octree_depth: 10
[INFO] mesh_point_weight: 4
[INFO] mesh_samples: 1.0
[INFO] mesh_size: 200000
[INFO] min_num_features: 8000
[INFO] mve_confidence: 0.6
[INFO] name: a44166b4-bd5c-4c63-adfc-c165b1b1fe8a
[INFO] opensfm_depthmap_method: PATCH_MATCH
[INFO] opensfm_depthmap_min_consistent_views: 3
[INFO] opensfm_depthmap_min_patch_sd: 1
[INFO] orthophoto_compression: DEFLATE
[INFO] orthophoto_cutline: False
[INFO] orthophoto_no_tiled: False
[INFO] orthophoto_png: False
[INFO] orthophoto_resolution: 5
[INFO] pc_classify: True
[INFO] pc_csv: False
[INFO] pc_ept: False
[INFO] pc_filter: 2.5
[INFO] pc_las: False
[INFO] pc_rectify: False
[INFO] pc_sample: 0
[INFO] project_path: /var/www/data
[INFO] radiometric_calibration: none
[INFO] rerun: None
[INFO] rerun_all: False
[INFO] rerun_from: None
[INFO] resize_to: 2048
[INFO] skip_3dmodel: False
[INFO] sm_cluster: None
[INFO] smrf_scalar: 1.25
[INFO] smrf_slope: 0.15
[INFO] smrf_threshold: 0.5
[INFO] smrf_window: 18.0
[INFO] split: 999999
[INFO] split_overlap: 150
[INFO] texturing_data_term: gmi
[INFO] texturing_keep_unseen_faces: False
[INFO] texturing_nadir_weight: 16
[INFO] texturing_outlier_removal_type: gauss_clamping
[INFO] texturing_skip_global_seam_leveling: False
[INFO] texturing_skip_hole_filling: False
[INFO] texturing_skip_local_seam_leveling: False
[INFO] texturing_skip_visibility_test: False
[INFO] texturing_tone_mapping: none
[INFO] time: False
[INFO] use_3dmesh: True
[INFO] use_exif: False
[INFO] use_fixed_camera_params: False
[INFO] use_hybrid_bundle_adjustment: False
[INFO] use_opensfm_dense: False
[INFO] verbose: False
[INFO] ==============
[INFO] Running dataset stage
[INFO] Loading dataset from: /var/www/data/a44166b4-bd5c-4c63-adfc-c165b1b1fe8a/images
[INFO] Loading 54 images
[INFO] Wrote images database: /var/www/data/a44166b4-bd5c-4c63-adfc-c165b1b1fe8a/images.json
[INFO] Found 54 usable images
[INFO] Parsing SRS header: WGS84 UTM 29N
[INFO] Finished dataset stage
[INFO] Running split stage
[INFO] Normal dataset, will process all at once.
[INFO] Finished split stage
[INFO] Running merge stage
[INFO] Normal dataset, nothing to merge.
[INFO] Finished merge stage
[INFO] Running opensfm stage
[INFO] Altitude data detected, enabling it for GPS alignment
[INFO] [‘use_exif_size: no’, ‘feature_process_size: 2048’, ‘feature_min_frames: 8000’, ‘processes: 4’, ‘matching_gps_neighbors: 8’, ‘matching_gps_distance: 0’, ‘depthmap_method: PATCH_MATCH’, ‘depthmap_resolution: 640’, ‘depthmap_min_patch_sd: 1’, ‘depthmap_min_consistent_views: 3’, ‘optimize_camera_parameters: yes’, ‘undistorted_image_format: tif’, ‘bundle_outlier_filtering_type: AUTO’, ‘align_orientation_prior: vertical’, ‘triangulation_type: ROBUST’, ‘bundle_common_position_constraints: no’, ‘feature_type: SIFT’, ‘use_altitude_tag: yes’, ‘align_method: auto’, ‘local_bundle_radius: 0’]
[INFO] running /usr/bin/env python2 /code/SuperBuild/src/opensfm/bin/opensfm extract_metadata “/var/www/data/a44166b4-bd5c-4c63-adfc-c165b1b1fe8a/opensfm”
2020-03-21 09:04:34,987 INFO: Extracting EXIF for org_47cb4925105cd42c_1584711264000.jpg
2020-03-21 09:04:35,021 INFO: Extracting EXIF for org_c03b03bccb220d51_1584711096000.jpg
2020-03-21 09:04:35,042 INFO: Extracting EXIF for org_2776e17a8f246489_1584711380000.jpg
2020-03-21 09:04:35,062 INFO: Extracting EXIF for org_4a5839327bf9ba41_1584711138000.jpg
2020-03-21 09:04:35,083 INFO: Extracting EXIF for org_e58f55243f1827cc_1584711236000.jpg
2020-03-21 09:04:35,102 INFO: Extracting EXIF for org_a3fcd5412197982a_1584711242000.jpg
2020-03-21 09:04:35,123 INFO: Extracting EXIF for org_2b654c60fa2ba96b_1584711166000.jpg
2020-03-21 09:04:35,144 INFO: Extracting EXIF for org_6cde811f587c5e72_1584711030000.jpg
2020-03-21 09:04:35,164 INFO: Extracting EXIF for org_bbd3968ede9a953d_1584711200000.jpg
2020-03-21 09:04:35,183 INFO: Extracting EXIF for org_6710d775b75358cf_1584711402000.jpg
2020-03-21 09:04:35,202 INFO: Extracting EXIF for org_662b6e48c4a0a2f2_1584711412000.jpg
2020-03-21 09:04:35,221 INFO: Extracting EXIF for org_d8f98e8bcdbda9ae_1584711134000.jpg
2020-03-21 09:04:35,242 INFO: Extracting EXIF for org_21565ea8a9b1dd5f_1584711212000.jpg
2020-03-21 09:04:35,262 INFO: Extracting EXIF for org_4ef2af59f9eea5a5_1584711300000.jpg
2020-03-21 09:04:35,282 INFO: Extracting EXIF for org_31790d6fc211671d_1584711328000.jpg
2020-03-21 09:04:35,302 INFO: Extracting EXIF for org_88f28f44becee434_1584711340000.jpg
2020-03-21 09:04:35,321 INFO: Extracting EXIF for org_a99aa1ec2b316b4d_1584711186000.jpg
2020-03-21 09:04:35,341 INFO: Extracting EXIF for org_bf874feb63b56cf7_1584711432000.jpg
2020-03-21 09:04:35,361 INFO: Extracting EXIF for org_6ac61a67f61f042e_1584711106000.jpg
2020-03-21 09:04:35,380 INFO: Extracting EXIF for org_f975245295800c4a_1584711174000.jpg
2020-03-21 09:04:35,400 INFO: Extracting EXIF for org_86c367775ec37503_1584711294000.jpg
2020-03-21 09:04:35,419 INFO: Extracting EXIF for org_9cddea4894c9f2b8_1584711064000.jpg
2020-03-21 09:04:35,439 INFO: Extracting EXIF for org_196aa761d88dfde9_1584711318000.jpg
2020-03-21 09:04:35,459 INFO: Extracting EXIF for org_9c1e8818b7584285_1584711348000.jpg
2020-03-21 09:04:35,480 INFO: Extracting EXIF for org_dd7739e1b1a56ab3_1584711334000.jpg
2020-03-21 09:04:35,507 INFO: Extracting EXIF for org_3e3ebacdf897e708_1584711390000.jpg
2020-03-21 09:04:35,528 INFO: Extracting EXIF for org_f10b526907e4691f_1584711054000.jpg
2020-03-21 09:04:35,547 INFO: Extracting EXIF for org_fd5266accdabd50c_1584711248000.jpg
2020-03-21 09:04:35,566 INFO: Extracting EXIF for org_c7fd8dfdd92f3aa1_1584711252000.jpg
2020-03-21 09:04:35,586 INFO: Extracting EXIF for org_225020018fe9b662_1584711366000.jpg
2020-03-21 09:04:35,607 INFO: Extracting EXIF for org_931030babffa7a96_1584711048000.jpg
2020-03-21 09:04:35,628 INFO: Extracting EXIF for org_1b78d82499e302b0_1584711418000.jpg
2020-03-21 09:04:35,647 INFO: Extracting EXIF for org_0a70f4a3054d5021_1584711354000.jpg
2020-03-21 09:04:35,666 INFO: Extracting EXIF for org_80b8c349a9d3ee47_1584711078000.jpg
2020-03-21 09:04:35,686 INFO: Extracting EXIF for org_f4989c4cea90f678_1584711288000.jpg
2020-03-21 09:04:35,706 INFO: Extracting EXIF for org_00428a0cfe96ff46_1584711224000.jpg
2020-03-21 09:04:35,725 INFO: Extracting EXIF for org_4bd9975a0084a5f5_1584711426000.jpg
2020-03-21 09:04:35,744 INFO: Extracting EXIF for org_78c8f10cecfdd02d_1584711218000.jpg
2020-03-21 09:04:35,764 INFO: Extracting EXIF for org_a3f933de03f1eb75_1584711230000.jpg
2020-03-21 09:04:35,783 INFO: Extracting EXIF for org_a94c1bd77afc487f_1584711394000.jpg
2020-03-21 09:04:35,802 INFO: Extracting EXIF for org_90b93d4ba53ba8e2_1584711148000.jpg
2020-03-21 09:04:35,821 INFO: Extracting EXIF for org_2f95383df2cf7aa7_1584711126000.jpg
2020-03-21 09:04:35,841 INFO: Extracting EXIF for org_227ab3cb6dd6d88b_1584711312000.jpg
2020-03-21 09:04:35,859 INFO: Extracting EXIF for org_0d1395fad56f2d22_1584711206000.jpg
2020-03-21 09:04:35,878 INFO: Extracting EXIF for org_45187a0f6ad532d4_1584711360000.jpg
2020-03-21 09:04:35,897 INFO: Extracting EXIF for org_9fa9471f63c3a172_1584711322000.jpg
2020-03-21 09:04:35,916 INFO: Extracting EXIF for org_ee011951938170f3_1584711272000.jpg
2020-03-21 09:04:35,937 INFO: Extracting EXIF for org_3bbe67d2d95b56c4_1584711258000.jpg
2020-03-21 09:04:35,957 INFO: Extracting EXIF for org_c4df73f80226f947_1584711278000.jpg
2020-03-21 09:04:35,978 INFO: Extracting EXIF for org_c90c3c2c4490d81c_1584711040000.jpg
2020-03-21 09:04:35,997 INFO: Extracting EXIF for org_35f300c308c3092c_1584711372000.jpg
2020-03-21 09:04:36,017 INFO: Extracting EXIF for org_059a8978fb3a60ca_1584711422000.jpg
2020-03-21 09:04:36,036 INFO: Extracting EXIF for org_acf0bca8a2738ec3_1584711376000.jpg
2020-03-21 09:04:36,055 INFO: Extracting EXIF for org_d1c2a2b5b7b1c882_1584711306000.jpg
[INFO] running /usr/bin/env python2 /code/SuperBuild/src/opensfm/bin/opensfm detect_features “/var/www/data/a44166b4-bd5c-4c63-adfc-c165b1b1fe8a/opensfm”
2020-03-21 09:04:39,081 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:39,729 INFO: Extracting ROOT_SIFT features for image org_c03b03bccb220d51_1584711096000.jpg
2020-03-21 09:04:39,919 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:40,815 DEBUG: Found 12908 points in 1.73345088959s
2020-03-21 09:04:40,815 DEBUG: done
2020-03-21 09:04:40,885 INFO: Extracting ROOT_SIFT features for image org_2776e17a8f246489_1584711380000.jpg
2020-03-21 09:04:41,081 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:42,263 INFO: Extracting ROOT_SIFT features for image org_4a5839327bf9ba41_1584711138000.jpg
2020-03-21 09:04:42,379 DEBUG: Found 15923 points in 2.45967197418s
2020-03-21 09:04:42,380 DEBUG: done
2020-03-21 09:04:42,497 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:43,461 DEBUG: No segmentation for org_47cb4925105cd42c_1584711264000.jpg, no features masked.
2020-03-21 09:04:43,592 DEBUG: Found 14290 points in 2.51080918312s
2020-03-21 09:04:43,594 DEBUG: done
2020-03-21 09:04:44,400 INFO: Extracting ROOT_SIFT features for image org_e58f55243f1827cc_1584711236000.jpg
2020-03-21 09:04:44,931 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:45,136 DEBUG: Found 10967 points in 2.63844799995s
2020-03-21 09:04:45,137 DEBUG: done
2020-03-21 09:04:45,261 DEBUG: No segmentation for org_c03b03bccb220d51_1584711096000.jpg, no features masked.
2020-03-21 09:04:46,272 DEBUG: No segmentation for org_2776e17a8f246489_1584711380000.jpg, no features masked.
2020-03-21 09:04:46,531 INFO: Extracting ROOT_SIFT features for image org_a3fcd5412197982a_1584711242000.jpg
2020-03-21 09:04:46,747 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:47,072 DEBUG: Found 5377 points in 2.14092588425s
2020-03-21 09:04:47,072 DEBUG: reducing threshold
2020-03-21 09:04:47,072 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:04:47,599 DEBUG: No segmentation for org_4a5839327bf9ba41_1584711138000.jpg, no features masked.
2020-03-21 09:04:47,696 INFO: Extracting ROOT_SIFT features for image org_2b654c60fa2ba96b_1584711166000.jpg
2020-03-21 09:04:47,931 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:48,306 INFO: Extracting ROOT_SIFT features for image org_6cde811f587c5e72_1584711030000.jpg
2020-03-21 09:04:48,607 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:49,018 DEBUG: Found 5548 points in 2.27082705498s
2020-03-21 09:04:49,018 DEBUG: reducing threshold
2020-03-21 09:04:49,018 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:04:49,121 DEBUG: Found 12639 points in 2.04871201515s
2020-03-21 09:04:49,122 DEBUG: done
2020-03-21 09:04:50,248 DEBUG: Found 6636 points in 2.31554818153s
2020-03-21 09:04:50,248 DEBUG: reducing threshold
2020-03-21 09:04:50,248 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:04:50,704 DEBUG: Found 10536 points in 2.09621500969s
2020-03-21 09:04:50,704 DEBUG: done
2020-03-21 09:04:51,593 DEBUG: Found 15246 points in 2.5745139122s
2020-03-21 09:04:51,593 DEBUG: done
2020-03-21 09:04:51,714 DEBUG: No segmentation for org_e58f55243f1827cc_1584711236000.jpg, no features masked.
2020-03-21 09:04:52,425 INFO: Extracting ROOT_SIFT features for image org_bbd3968ede9a953d_1584711200000.jpg
2020-03-21 09:04:52,931 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:53,358 DEBUG: Found 15444 points in 3.10938215256s
2020-03-21 09:04:53,358 DEBUG: done
2020-03-21 09:04:53,506 DEBUG: No segmentation for org_6cde811f587c5e72_1584711030000.jpg, no features masked.
2020-03-21 09:04:53,932 DEBUG: No segmentation for org_a3fcd5412197982a_1584711242000.jpg, no features masked.
2020-03-21 09:04:54,164 INFO: Extracting ROOT_SIFT features for image org_6710d775b75358cf_1584711402000.jpg
2020-03-21 09:04:54,354 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:54,775 INFO: Extracting ROOT_SIFT features for image org_662b6e48c4a0a2f2_1584711412000.jpg
2020-03-21 09:04:55,057 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:55,374 DEBUG: Found 10163 points in 2.44257283211s
2020-03-21 09:04:55,375 DEBUG: done
2020-03-21 09:04:55,873 DEBUG: No segmentation for org_2b654c60fa2ba96b_1584711166000.jpg, no features masked.
2020-03-21 09:04:56,855 DEBUG: Found 6136 points in 2.49914598465s
2020-03-21 09:04:56,856 DEBUG: reducing threshold
2020-03-21 09:04:56,856 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:04:56,936 INFO: Extracting ROOT_SIFT features for image org_d8f98e8bcdbda9ae_1584711134000.jpg
2020-03-21 09:04:57,194 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:57,547 DEBUG: Found 4515 points in 2.4901881218s
2020-03-21 09:04:57,548 DEBUG: reducing threshold
2020-03-21 09:04:57,548 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:04:57,905 DEBUG: No segmentation for org_bbd3968ede9a953d_1584711200000.jpg, no features masked.
2020-03-21 09:04:58,480 INFO: Extracting ROOT_SIFT features for image org_21565ea8a9b1dd5f_1584711212000.jpg
2020-03-21 09:04:58,896 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:04:59,317 DEBUG: Found 14338 points in 2.46124100685s
2020-03-21 09:04:59,317 DEBUG: done
2020-03-21 09:04:59,381 DEBUG: Found 12644 points in 2.18611121178s
2020-03-21 09:04:59,381 DEBUG: done
2020-03-21 09:04:59,734 DEBUG: Found 11002 points in 2.18573594093s
2020-03-21 09:04:59,734 DEBUG: done
2020-03-21 09:05:02,339 DEBUG: Found 9317 points in 3.44324398041s
2020-03-21 09:05:02,340 DEBUG: done
2020-03-21 09:05:02,553 DEBUG: No segmentation for org_d8f98e8bcdbda9ae_1584711134000.jpg, no features masked.
2020-03-21 09:05:02,785 DEBUG: No segmentation for org_6710d775b75358cf_1584711402000.jpg, no features masked.
2020-03-21 09:05:02,971 DEBUG: No segmentation for org_662b6e48c4a0a2f2_1584711412000.jpg, no features masked.
2020-03-21 09:05:03,317 INFO: Extracting ROOT_SIFT features for image org_4ef2af59f9eea5a5_1584711300000.jpg
2020-03-21 09:05:03,489 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:03,587 INFO: Extracting ROOT_SIFT features for image org_31790d6fc211671d_1584711328000.jpg
2020-03-21 09:05:03,643 INFO: Extracting ROOT_SIFT features for image org_88f28f44becee434_1584711340000.jpg
2020-03-21 09:05:03,873 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:03,916 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:04,386 DEBUG: No segmentation for org_21565ea8a9b1dd5f_1584711212000.jpg, no features masked.
2020-03-21 09:05:04,912 INFO: Extracting ROOT_SIFT features for image org_a99aa1ec2b316b4d_1584711186000.jpg
2020-03-21 09:05:05,171 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:05,776 DEBUG: Found 3445 points in 2.28733205795s
2020-03-21 09:05:05,776 DEBUG: reducing threshold
2020-03-21 09:05:05,777 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:05,951 DEBUG: Found 8036 points in 2.03536510468s
2020-03-21 09:05:05,952 DEBUG: done
2020-03-21 09:05:06,271 DEBUG: Found 10166 points in 2.39761781693s
2020-03-21 09:05:06,271 DEBUG: done
2020-03-21 09:05:07,582 DEBUG: Found 10345 points in 2.41125297546s
2020-03-21 09:05:07,582 DEBUG: done
2020-03-21 09:05:08,289 DEBUG: Found 9712 points in 2.51226806641s
2020-03-21 09:05:08,289 DEBUG: done
2020-03-21 09:05:08,301 DEBUG: No segmentation for org_31790d6fc211671d_1584711328000.jpg, no features masked.
2020-03-21 09:05:08,792 DEBUG: No segmentation for org_88f28f44becee434_1584711340000.jpg, no features masked.
2020-03-21 09:05:08,853 INFO: Extracting ROOT_SIFT features for image org_bf874feb63b56cf7_1584711432000.jpg
2020-03-21 09:05:09,051 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:09,376 INFO: Extracting ROOT_SIFT features for image org_6ac61a67f61f042e_1584711106000.jpg
2020-03-21 09:05:09,798 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:10,111 DEBUG: No segmentation for org_a99aa1ec2b316b4d_1584711186000.jpg, no features masked.
2020-03-21 09:05:10,324 DEBUG: No segmentation for org_4ef2af59f9eea5a5_1584711300000.jpg, no features masked.
2020-03-21 09:05:10,741 INFO: Extracting ROOT_SIFT features for image org_f975245295800c4a_1584711174000.jpg
2020-03-21 09:05:10,946 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:11,042 INFO: Extracting ROOT_SIFT features for image org_86c367775ec37503_1584711294000.jpg
2020-03-21 09:05:11,329 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:11,348 DEBUG: Found 10488 points in 2.29641509056s
2020-03-21 09:05:11,348 DEBUG: done
2020-03-21 09:05:12,018 DEBUG: Found 16113 points in 2.22009921074s
2020-03-21 09:05:12,018 DEBUG: done
2020-03-21 09:05:12,995 DEBUG: Found 6740 points in 2.04917097092s
2020-03-21 09:05:12,996 DEBUG: reducing threshold
2020-03-21 09:05:12,996 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:13,987 DEBUG: Found 5249 points in 2.65730690956s
2020-03-21 09:05:13,988 DEBUG: reducing threshold
2020-03-21 09:05:13,988 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:14,292 DEBUG: No segmentation for org_bf874feb63b56cf7_1584711432000.jpg, no features masked.
2020-03-21 09:05:14,599 DEBUG: No segmentation for org_6ac61a67f61f042e_1584711106000.jpg, no features masked.
2020-03-21 09:05:14,965 INFO: Extracting ROOT_SIFT features for image org_9cddea4894c9f2b8_1584711064000.jpg
2020-03-21 09:05:15,335 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:15,545 DEBUG: Found 16839 points in 2.54902386665s
2020-03-21 09:05:15,545 DEBUG: done
2020-03-21 09:05:15,920 INFO: Extracting ROOT_SIFT features for image org_196aa761d88dfde9_1584711318000.jpg
2020-03-21 09:05:16,120 DEBUG: Found 14168 points in 2.13167595863s
2020-03-21 09:05:16,120 DEBUG: done
2020-03-21 09:05:16,185 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:17,880 DEBUG: Found 15820 points in 2.54426407814s
2020-03-21 09:05:17,880 DEBUG: done
2020-03-21 09:05:18,321 DEBUG: No segmentation for org_f975245295800c4a_1584711174000.jpg, no features masked.
2020-03-21 09:05:18,471 DEBUG: Found 7662 points in 2.28560495377s
2020-03-21 09:05:18,471 DEBUG: reducing threshold
2020-03-21 09:05:18,471 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:19,197 DEBUG: No segmentation for org_86c367775ec37503_1584711294000.jpg, no features masked.
2020-03-21 09:05:19,355 INFO: Extracting ROOT_SIFT features for image org_9c1e8818b7584285_1584711348000.jpg
2020-03-21 09:05:19,581 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:20,515 INFO: Extracting ROOT_SIFT features for image org_dd7739e1b1a56ab3_1584711334000.jpg
2020-03-21 09:05:20,667 DEBUG: Found 15281 points in 2.1960580349s
2020-03-21 09:05:20,668 DEBUG: done
2020-03-21 09:05:20,757 DEBUG: No segmentation for org_9cddea4894c9f2b8_1584711064000.jpg, no features masked.
2020-03-21 09:05:20,798 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:21,796 INFO: Extracting ROOT_SIFT features for image org_3e3ebacdf897e708_1584711390000.jpg
2020-03-21 09:05:21,914 DEBUG: Found 8162 points in 2.33176112175s
2020-03-21 09:05:21,914 DEBUG: done
2020-03-21 09:05:22,012 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:23,098 DEBUG: Found 6825 points in 2.29954385757s
2020-03-21 09:05:23,099 DEBUG: reducing threshold
2020-03-21 09:05:23,099 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:23,309 DEBUG: No segmentation for org_196aa761d88dfde9_1584711318000.jpg, no features masked.
2020-03-21 09:05:24,224 DEBUG: No segmentation for org_9c1e8818b7584285_1584711348000.jpg, no features masked.
2020-03-21 09:05:24,379 DEBUG: Found 12350 points in 2.36752891541s
2020-03-21 09:05:24,380 DEBUG: done
2020-03-21 09:05:24,669 INFO: Extracting ROOT_SIFT features for image org_f10b526907e4691f_1584711054000.jpg
2020-03-21 09:05:24,762 INFO: Extracting ROOT_SIFT features for image org_fd5266accdabd50c_1584711248000.jpg
2020-03-21 09:05:25,053 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:25,110 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:25,292 DEBUG: Found 14708 points in 2.19260287285s
2020-03-21 09:05:25,292 DEBUG: done
2020-03-21 09:05:26,433 DEBUG: No segmentation for org_3e3ebacdf897e708_1584711390000.jpg, no features masked.
2020-03-21 09:05:27,567 DEBUG: Found 7969 points in 2.45746994019s
2020-03-21 09:05:27,568 DEBUG: reducing threshold
2020-03-21 09:05:27,568 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:27,631 DEBUG: Found 10056 points in 2.57279896736s
2020-03-21 09:05:27,631 DEBUG: done
2020-03-21 09:05:27,972 INFO: Extracting ROOT_SIFT features for image org_c7fd8dfdd92f3aa1_1584711252000.jpg
2020-03-21 09:05:28,172 DEBUG: No segmentation for org_dd7739e1b1a56ab3_1584711334000.jpg, no features masked.
2020-03-21 09:05:28,207 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:29,117 INFO: Extracting ROOT_SIFT features for image org_225020018fe9b662_1584711366000.jpg
2020-03-21 09:05:29,627 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:29,772 DEBUG: Found 19672 points in 2.20429420471s
2020-03-21 09:05:29,772 DEBUG: done
2020-03-21 09:05:29,878 DEBUG: No segmentation for org_f10b526907e4691f_1584711054000.jpg, no features masked.
2020-03-21 09:05:30,582 INFO: Extracting ROOT_SIFT features for image org_931030babffa7a96_1584711048000.jpg
2020-03-21 09:05:30,607 DEBUG: Found 12724 points in 2.40020704269s
2020-03-21 09:05:30,607 DEBUG: done
2020-03-21 09:05:30,807 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:31,931 DEBUG: Found 4938 points in 2.30400013924s
2020-03-21 09:05:31,932 DEBUG: reducing threshold
2020-03-21 09:05:31,932 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:32,687 DEBUG: No segmentation for org_fd5266accdabd50c_1584711248000.jpg, no features masked.
2020-03-21 09:05:33,396 DEBUG: No segmentation for org_c7fd8dfdd92f3aa1_1584711252000.jpg, no features masked.
2020-03-21 09:05:33,558 DEBUG: Found 11698 points in 2.75087404251s
2020-03-21 09:05:33,558 DEBUG: done
2020-03-21 09:05:34,232 INFO: Extracting ROOT_SIFT features for image org_1b78d82499e302b0_1584711418000.jpg
2020-03-21 09:05:34,267 INFO: Extracting ROOT_SIFT features for image org_0a70f4a3054d5021_1584711354000.jpg
2020-03-21 09:05:34,333 DEBUG: Found 11953 points in 2.40059304237s
2020-03-21 09:05:34,333 DEBUG: done
2020-03-21 09:05:34,455 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:34,481 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:35,864 DEBUG: No segmentation for org_931030babffa7a96_1584711048000.jpg, no features masked.
2020-03-21 09:05:36,864 DEBUG: Found 5499 points in 2.40910696983s
2020-03-21 09:05:36,865 DEBUG: reducing threshold
2020-03-21 09:05:36,865 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:36,944 DEBUG: Found 3456 points in 2.46303391457s
2020-03-21 09:05:36,944 DEBUG: reducing threshold
2020-03-21 09:05:36,945 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:37,021 DEBUG: No segmentation for org_225020018fe9b662_1584711366000.jpg, no features masked.
2020-03-21 09:05:37,178 INFO: Extracting ROOT_SIFT features for image org_80b8c349a9d3ee47_1584711078000.jpg
2020-03-21 09:05:37,384 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:37,646 INFO: Extracting ROOT_SIFT features for image org_f4989c4cea90f678_1584711288000.jpg
2020-03-21 09:05:37,836 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:38,740 DEBUG: Found 11882 points in 1.87540388107s
2020-03-21 09:05:38,741 DEBUG: done
2020-03-21 09:05:39,052 DEBUG: Found 9634 points in 2.10742497444s
2020-03-21 09:05:39,053 DEBUG: done
2020-03-21 09:05:39,728 DEBUG: Found 19668 points in 2.3436229229s
2020-03-21 09:05:39,728 DEBUG: done
2020-03-21 09:05:40,148 DEBUG: Found 12775 points in 2.311013937s
2020-03-21 09:05:40,148 DEBUG: done
2020-03-21 09:05:41,386 DEBUG: No segmentation for org_0a70f4a3054d5021_1584711354000.jpg, no features masked.
2020-03-21 09:05:41,490 DEBUG: No segmentation for org_1b78d82499e302b0_1584711418000.jpg, no features masked.
2020-03-21 09:05:42,194 INFO: Extracting ROOT_SIFT features for image org_00428a0cfe96ff46_1584711224000.jpg
2020-03-21 09:05:42,520 INFO: Extracting ROOT_SIFT features for image org_4bd9975a0084a5f5_1584711426000.jpg
2020-03-21 09:05:42,631 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:42,901 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:43,178 DEBUG: No segmentation for org_80b8c349a9d3ee47_1584711078000.jpg, no features masked.
2020-03-21 09:05:43,284 DEBUG: No segmentation for org_f4989c4cea90f678_1584711288000.jpg, no features masked.
2020-03-21 09:05:43,978 INFO: Extracting ROOT_SIFT features for image org_78c8f10cecfdd02d_1584711218000.jpg
2020-03-21 09:05:44,313 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:44,584 INFO: Extracting ROOT_SIFT features for image org_a3f933de03f1eb75_1584711230000.jpg
2020-03-21 09:05:44,762 DEBUG: Found 5532 points in 2.1298699379s
2020-03-21 09:05:44,762 DEBUG: reducing threshold
2020-03-21 09:05:44,762 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:44,849 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:45,017 DEBUG: Found 7207 points in 2.11510801315s
2020-03-21 09:05:45,017 DEBUG: reducing threshold
2020-03-21 09:05:45,017 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:46,267 DEBUG: Found 7079 points in 1.95285797119s
2020-03-21 09:05:46,267 DEBUG: reducing threshold
2020-03-21 09:05:46,267 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:47,047 DEBUG: Found 12026 points in 2.28517985344s
2020-03-21 09:05:47,048 DEBUG: done
2020-03-21 09:05:47,104 DEBUG: Found 4061 points in 2.25461792946s
2020-03-21 09:05:47,104 DEBUG: reducing threshold
2020-03-21 09:05:47,104 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:47,504 DEBUG: Found 14352 points in 2.48678207397s
2020-03-21 09:05:47,504 DEBUG: done
2020-03-21 09:05:48,963 DEBUG: Found 14420 points in 2.69583201408s
2020-03-21 09:05:48,964 DEBUG: done
2020-03-21 09:05:49,484 DEBUG: No segmentation for org_00428a0cfe96ff46_1584711224000.jpg, no features masked.
2020-03-21 09:05:49,614 DEBUG: Found 10831 points in 2.49590611458s
2020-03-21 09:05:49,614 DEBUG: done
2020-03-21 09:05:50,232 DEBUG: No segmentation for org_4bd9975a0084a5f5_1584711426000.jpg, no features masked.
2020-03-21 09:05:50,430 INFO: Extracting ROOT_SIFT features for image org_a94c1bd77afc487f_1584711394000.jpg
2020-03-21 09:05:50,779 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:51,107 INFO: Extracting ROOT_SIFT features for image org_90b93d4ba53ba8e2_1584711148000.jpg
2020-03-21 09:05:51,435 DEBUG: No segmentation for org_78c8f10cecfdd02d_1584711218000.jpg, no features masked.
2020-03-21 09:05:51,694 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:52,120 DEBUG: No segmentation for org_a3f933de03f1eb75_1584711230000.jpg, no features masked.
2020-03-21 09:05:52,520 INFO: Extracting ROOT_SIFT features for image org_2f95383df2cf7aa7_1584711126000.jpg
2020-03-21 09:05:52,879 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:52,924 INFO: Extracting ROOT_SIFT features for image org_227ab3cb6dd6d88b_1584711312000.jpg
2020-03-21 09:05:53,080 DEBUG: Found 7372 points in 2.30094790459s
2020-03-21 09:05:53,080 DEBUG: reducing threshold
2020-03-21 09:05:53,080 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:53,173 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:53,844 DEBUG: Found 5320 points in 2.15001702309s
2020-03-21 09:05:53,844 DEBUG: reducing threshold
2020-03-21 09:05:53,844 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:55,145 DEBUG: Found 16053 points in 2.26570296288s
2020-03-21 09:05:55,148 DEBUG: done
2020-03-21 09:05:55,204 DEBUG: Found 17177 points in 2.1235370636s
2020-03-21 09:05:55,205 DEBUG: done
2020-03-21 09:05:55,618 DEBUG: Found 4915 points in 2.44457697868s
2020-03-21 09:05:55,618 DEBUG: reducing threshold
2020-03-21 09:05:55,618 DEBUG: Computing sift with threshold 0.0666666666667
2020-03-21 09:05:56,314 DEBUG: Found 13605 points in 2.46970701218s
2020-03-21 09:05:56,315 DEBUG: done
2020-03-21 09:05:58,116 DEBUG: Found 11179 points in 2.49675583839s
2020-03-21 09:05:58,116 DEBUG: done
2020-03-21 09:05:58,332 DEBUG: No segmentation for org_a94c1bd77afc487f_1584711394000.jpg, no features masked.
2020-03-21 09:05:58,524 DEBUG: No segmentation for org_2f95383df2cf7aa7_1584711126000.jpg, no features masked.
2020-03-21 09:05:59,388 INFO: Extracting ROOT_SIFT features for image org_0d1395fad56f2d22_1584711206000.jpg
2020-03-21 09:05:59,531 DEBUG: No segmentation for org_90b93d4ba53ba8e2_1584711148000.jpg, no features masked.
2020-03-21 09:05:59,676 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:05:59,768 INFO: Extracting ROOT_SIFT features for image org_45187a0f6ad532d4_1584711360000.jpg
2020-03-21 09:06:00,178 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:06:00,347 DEBUG: No segmentation for org_227ab3cb6dd6d88b_1584711312000.jpg, no features masked.
2020-03-21 09:06:00,562 INFO: Extracting ROOT_SIFT features for image org_9fa9471f63c3a172_1584711322000.jpg
2020-03-21 09:06:00,773 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:06:00,983 INFO: Extracting ROOT_SIFT features for image org_ee011951938170f3_1584711272000.jpg
2020-03-21 09:06:01,321 DEBUG: Computing sift with threshold 0.1
2020-03-21 09:06:01,709 DEBUG: Found 11183 points in 2.03317308426s
2020-03-21 09:06:01,709 DEBUG: done

Hey @Tara_H :hand: the contours and elevation colors are calculated from the DSM. How does the point cloud look like (can you post an annotated screenshot)?

Thanks for the reply @pierotofy !

The point cloud looks ok in the sense that the buildings, trees etc are above the ground rather than below it, but looking at the side view (assuming I haven’t just rotated it somehow) the slope of the ground does seem to be incorrect in the same way that the contour map would indicate:
image

In reality the area to the right is the vegetable garden on relatively high ground, whereas the area on the left should slope down away from the house and will ultimately be a pond.

For comparison purposes, the road (marked L4504) seen in the first post runs along the edge of the point cloud closest to the camera in the image above. Here’s a picture of the point cloud from the same direction but tilted forward:
image

Could this then be an example of the bowl distortion that I’ve seen in other threads? Would that present itself like this? Ultimately I want to use these maps for permaculture planning so it’s vital that I do get an accurate contour map, that being the reason I bought the drone in the first place!

1 Like

Yes the problem is likely in the data acquisition (causing the small bowling effect). Check out https://docs.opendronemap.org/tutorials.html#calibrating-the-camera for tips on flying. Note that for really accurate elevation results you should employ ground control points.

2 Likes

Thanks @pierotofy that makes sense - unfortunately the mavic mini is not yet supported for DroneDeploy or similar tools so I have to fly the path manually which makes it a bit more difficult to get an exact grid as described. Last I saw it was planned for next month so maybe I’ll just need to wait a bit longer for that part.

I was actually reading up on ground control points this morning but from what I can discover, they have to be placed using specialist equipment to be sufficiently accurate (i.e. phone gps or similar will not be good enough) and the equipment I saw was in the range of €1000 which is a bit outside my budget, especially since I won’t be using it on a regular basis. Am I correct in my understanding there, or would gcps placed using phone gps still give me enough improvement to be worth doing?

A phone is probably not good enough.

A decent phone GPS will get you, at best, to about ±3m horizontal and ±10m vertical. Is it better than nothing? Yes, but only just. Any GPS unit that puts out raw NMEA sentences (U-Blox M8-T, older firmware M8-N, etc.) can also be post-corrected (PPK) with something like RTKlib or possibly Trimble Business Center.

When I first started my agricultural field survey I did take GCPs with both a Trimble Yuma and my phone. The phone was close enough (relative accuracy mattered most over absolute accuracy) to get a self-consistent surface.

2 Likes

You can get good results manually flying. Do what you did, and then also do an orbit around the property with stills as you go. The orbit will get you the additional angles that you need to correct lens distortion.

2 Likes