Artikel skriven 2022-04-22, återbesökt 2025-12-28

Mäta årringar med din telefon

Del 1: Finns det behov av en app för att räkna årringar?

        Del 2: Borrkärnor

          ModelLensMin Focus Distance (Observed)Min Focus Distance (Apple)ApertureFOVPixel per MM (Observed)Pixel per MM (Apple)
          iPhone 17 Pro MaxUltrawide20 mm20 mm2.2106.2--
          iPhone 17 Pro MaxWide145 mm200 mm1.7872.04--
          iPhone 17 Pro MaxTele750 mm1160 mm2.814.3--
          iPhone 16 ProUltrawide20 mm20 mm2.2106.2--
          iPhone 16 ProWide155 mm200 mm1.7872.04--
          iPhone 16 ProTele900 mm1350 mm2.816.4--
          iPhone 15 Pro MaxUltrawide20 mm20 mm2.2106.2--
          iPhone 15 Pro MaxWide180 mm200 mm1.7872.04--
          iPhone 15 Pro MaxTele900 mm1350 mm2.816.41--
          iPhone 15Ultrawide100 mm-2.4106.56--
          iPhone 15Wide100 mm150 mm1.668.16--
          iPhone 14 ProUltrawide20 mm20 mm2.2106.2--
          iPhone 14 ProWide160 mm200 mm1.7871.2932.2-
          iPhone 13 ProUltrawide-20 mm1.8101.989.696.0
          iPhone 13 ProWide-150 mm1.567.133.621.5
          iPhone 13 ProTele---2.825.225.215.1
          iPhone 12 Pro MaxUltrawideNot sharp at close Dist.--2.4102.9--
          iPhone 12 Pro MaxWide120 mm150 mm1.667.732.321.5
          iPhone 12 Pro MaxTeleHard to get close-2.230.132.315.1
          iPhone 12 ProUltrawideNot sharp at close Dist.-2.4102.9--
          iPhone 12 ProWide100 mm120 mm1.667.140.326.8
          iPhone 12 ProTeleHard to get close-2.037.0--
          iPhone 11UltrawideNot sharp at close Dist.--2.4102.9--
          iPhone 11Wide-120 mm1.866.484327.1
          iPhone XRWide-120 mm1.8-36-
          iPhone SE2Wide-100 mm1.8---
          iPhone 7Wide-100 mm1.858.9844.337.2

          Comparison of photo quality between iPhone models

          iPhone 7 drill core image

          iPhone 7. Unsharp and problems with the white balance

          iPhone 8 drill core image

          iPhone 8. Unsharp and some problem with automatic white balance.

          iPhone SE2 drill core image

          iPhone SE2. Sharper and better white balance than the older phones above.

          iPhone XR drill core image

          iPhone XR. Similar result as iPhone SE2.

          iPhone 11 drill core image

          iPhone 11. Sharp. The quality is really good. Better than XR and SE2.

          iPhone 12 Pro Max drill core image

          iPhone 12 Pro Max. The minimum focus distance is larger than for the ordinary 12 Pro and 11. It Is harder to get sharp images.

          iPhone 13 Pro Ultrawide drill core image

          iPhone 13 Pro. UltraWide angle camera. Very sharp images. Will need special adjustments to avoid blurry edges.

          iPhone 13 Pro Wide drill core image

          iPhone 13 Pro. Wide angle camera. Not quite as good as 11,12 or 12 Pro.

          Image stitching process for drill cores

          Visual guide showing the stitching process

          App navigation between Camera, Image, and Table views

          Navigation flow between different views

              Del 3: Varför vi övergav projektet

                Drill core from Pine showing difficulty in counting annual rings

                Image 1: Drill core from Pine. It is hard to count the annual rings.

                Drill core from Pine with dirt making counting difficult

                Image 2: Drill core from Pine. You often get dirt on the drill core. It sometimes makes it harder to count and will make automatic counting even harder.

                Lärdomar

                Jag lärde mig mycket, inklusive följande:

                  Del 4: Återbesök av projektet 3 år senare

                  Under åren som följt har det funnits mycket intresse för ämnet. Det har också skett några förbättringar i kamerorna på telefonerna och det har också funnits några intressanta publikationer inom området.

                  Over the last five years, automated tree-ring detection has rapidly evolved from fragile, rule-based image processing toward robust deep-learning approaches. Early progress came from applying convolutional neural networks to ring-boundary segmentation, enabling far greater tolerance to noise, uneven sanding, and variable lighting. A major milestone was the use of instance-segmentation models such as Mask R-CNN to detect annual ring boundaries in both scanner and smartphone images (Kim et al., 2023). Shortly after, fully automated pipelines emerged that combine deep learning with post-processing and export to standard dendrochronology formats (Poláček et al., 2023). These methods were accompanied by open-source implementations, making state-of-the-art ring detection reproducible and accessible (TRG-ImageProcessing on GitHub). More recently, new annotated datasets and semantic-segmentation baselines have been released to address challenging hardwood surfaces and rough samples (Wu et al., 2024). Transformer-based segmentation models have also been applied to high-resolution wood microsections, improving boundary delineation in anatomically complex samples (García-Hidalgo et al., 2024). At the same time, large foundation segmentation models have lowered the barrier to interactive annotation and rapid prototyping (Kirillov et al., 2023). The open-source release of these models has accelerated experimentation across research and applied product development (Segment Anything on GitHub). Together, these advances now make high-precision, automated ring counting from photographs a realistic foundation for field-ready and mobile applications.

                  Vi har lagt till data för de senaste iPhone-linserna och kamerorna i listorna

                  Vi ser fram emot att se var allt detta kommer att sluta