Hi Loke.A couple of comments. 1) The 95 % success rate is very good. If you were to have a close look at the missed trees you may realize that the highest point on a particular palm tree is lower than the neighboring tree or palm frond. What ever algorithm you use, you are limited by the physical data, accuracy and resolution being the key factors. The physical condition of the trees you are trying to identify also plays a role,as mentioned previously. A DSM is an approximation as it is derived from some form of point data, either lidar or photo based and then generated by extracting the maximum, 95th percentile, maximum or perhaps the average height if all the points that land in a cell. Your issue is a limitation of the data and the basic logic of a max/minima algorithm. It cannot detect what is not reflected in the data. You can interpret the colour imagery but have a look at the dsm at the missed maxima.You could try developing a routine by processing the,raw point cloud data or try generating a dsm yourself. You can also try changing the algorithm parameters. Perhaps in areas if missed maxima. Although, this may not be effective as the maxima you are looking for probably is not reflected the dem.2) Plug-ins,are created by third parties and not by the Qgis team directly. You can reach out to the author and discuss with him/her. Kirk SchmidtSent from my Galaxy -------- Original message --------From: Loke Jian Munn via QGIS-User <[email protected]> Date: 2023-06-01 6:28 a.m. (GMT-04:00) To: [email protected] Cc: Moke Kwai Cheong <[email protected]>, Cheong Chee Phang <[email protected]>, Leong Kah Choon <[email protected]>, Mulwanto <[email protected]>, Endang Sudita Prayoga <[email protected]>, M Rizki Ramdani <[email protected]>, Fira Yunita <[email protected]>, Qurata Ayun Wijanarko <[email protected]> Subject: [Qgis-user] Palm Counting using QGIS
Hi Team, We have been using QGIS to do Palm Counting. Palm Counting here mean oil palm, we use QGIS processing tool, Features-Raster Tools (Local Minima and Maxima) to do the counting on a DSM layer. Example as below: Based on our industrial experiences, the accuracy of the Local Maxima algorithm is approximately 90%-95%. However, we still need to do toggle editing such as we utilize the “ Add Point Feature “ function when there are points missed, the “Vertex Tool” is used to adjust the position of points and the “Select Feature” for removal of any unnecessary points. We would like to have an improvement plan on the accuracy for more than 95% to reduce the extra manual works ( toggle edit ). Appreciate if the team could share with us any latest QGIS palm count plugin or any other solutions to achieve the accuracy more than 95% when doing palm count. Your input is highly appreciated. Thank you. Regards, Loke Jian Munn Information Technology (IT) Department KUALA LUMPUR KEPONG BERHAD Wisma Taiko, No. 1, Jalan S.P. Seenivasagam, 30000 Ipoh,Perak Darul Ridzuan,Malaysia T : +605 240 8000 (ext. 2443) DISCLAIMER : This email and any attachments are confidential and intended solely for the addressee. If you are not the intended recipient, any disclosure, copying, distribution either whole or partial, is prohibited and may be unlawful. In such case, please delete this message and kindly notify the sender. Kuala Lumpur Kepong Berhad DISCLAIMER : This email and any attachments are confidential and intended solely for the addressee. If you are not the intended recipient, any disclosure, copying, distribution either whole or partial, is prohibited and may be unlawful. In such case, please delete this message and kindly notify the sender. Kuala Lumpur Kepong Berhad
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