[{"id":37062,"web_url":"https://patchwork.libcamera.org/comment/37062/","msgid":"<176409280821.567526.12504756477774187335@ping.linuxembedded.co.uk>","date":"2025-11-25T17:46:48","subject":"Re: [PATCH v3 24/29] libcamera: dw100_vertexmap: Implement\n\tparametric dewarping","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Stefan Klug (2025-11-25 16:28:36)\n> Implement functions to allow lens dewarping based on the common lens\n> dewarp model used e.g. by OpenCV.\n> \n> See https://docs.opencv.org/4.12.0/d9/d0c/group__calib3d.html for an\n> in depth explanation of the parameters.\n> \n> Signed-off-by: Stefan Klug \n> Reviewed-by: Paul Elder \n> \n> ---\n> \n> Changes in v3:\n> - Fixed typo in docs\n> - Collected tag\n> \n> Changes in v2:\n> - Adapt to vertex map implementation based on affine transforms\n> - Improved documentation\n> - dropped loadDewarpParams function as it was never used\n> ---\n> .../converter/converter_dw100_vertexmap.h | 16 +++\n> .../converter/converter_dw100_vertexmap.cpp | 98 +++++++++++++++++--\n> 2 files changed, 108 insertions(+), 6 deletions(-)\n> \n> diff --git a/include/libcamera/internal/converter/converter_dw100_vertexmap.h b/include/libcamera/internal/converter/converter_dw100_vertexmap.h\n> index 428b3d74d4d2..49ecc81678a0 100644\n> --- a/include/libcamera/internal/converter/converter_dw100_vertexmap.h\n> +++ b/include/libcamera/internal/converter/converter_dw100_vertexmap.h\n> @@ -10,6 +10,9 @@\n> #include \n> #include \n> \n> +#include \"libcamera/internal/matrix.h\"\n> +#include \"libcamera/internal/vector.h\"\n> +\n> namespace libcamera {\n> \n> class Dw100VertexMap\n> @@ -50,9 +53,17 @@ public:\n> void setMode(const ScaleMode mode) { mode_ = mode; }\n> ScaleMode mode() const { return mode_; }\n> \n> + int setDewarpParams(const Matrix &cm, const Span &coeffs);\n> + bool dewarpParamsValid() { return dewarpParamsValid_; }\n> +\n> + void setLensDewarpEnable(bool enable) { lensDewarpEnable_ = enable; }\n> + bool lensDewarpEnable() { return lensDewarpEnable_; }\n> +\n> std::vector getVertexMap();\n> \n> private:\n> + Vector dewarpPoint(const Vector &p);\n> +\n> Rectangle scalerCrop_;\n> Rectangle sensorCrop_;\n> Transform transform_ = Transform::Identity;\n> @@ -66,6 +77,11 @@ private:\n> double effectiveScaleY_;\n> Point effectiveOffset_;\n> Rectangle effectiveScalerCrop_;\n> +\n> + Matrix dewarpM_ = Matrix::identity();\n> + std::array dewarpCoeffs_;\n> + bool lensDewarpEnable_ = true;\n> + bool dewarpParamsValid_ = false;\n> };\n> \n> } /* namespace libcamera */\n> diff --git a/src/libcamera/converter/converter_dw100_vertexmap.cpp b/src/libcamera/converter/converter_dw100_vertexmap.cpp\n> index 427d710743b8..b6880ba40a20 100644\n> --- a/src/libcamera/converter/converter_dw100_vertexmap.cpp\n> +++ b/src/libcamera/converter/converter_dw100_vertexmap.cpp\n> @@ -183,8 +183,6 @@ int dw100VerticesForLength(const int length)\n> * | | | | | Transpose) | | Rotate) |\n> * +-------------+ +-------------+ +------------+ +-----------------+\n> *\n> - * \\todo Lens dewarp is not yet implemented. An identity map is used instead.\n> - *\n> * All parameters are clamped to valid values before creating the vertex map.\n> *\n> * The constrains process works as follows:\n> @@ -544,10 +542,8 @@ std::vector Dw100VertexMap::getVertexMap()\n> \n> p = transformPoint(outputToSensor, p);\n> \n> - /*\n> - * \\todo: Transformations in sensor space to be added\n> - * here.\n> - */\n> + if (dewarpParamsValid_ && lensDewarpEnable_)\n> + p = dewarpPoint(p);\n> \n> p = transformPoint(sensorToInput, p);\n> \n> @@ -561,4 +557,94 @@ std::vector Dw100VertexMap::getVertexMap()\n> return res;\n> }\n> \n> +/**\n> + * \\brief Set the dewarp parameters\n> + * \\param cm The camera matrix\n> + * \\param coeffs The dewarp coefficients\n> + *\n> + * Sets the dewarp parameters according to the commonly used dewarp model. See\n> + * https://docs.opencv.org/4.12.0/d9/d0c/group__calib3d.html for further details\n> + * on the model. The parameter \\a coeffs must either hold 4,5,8 or 12 values.\n> + * They represent the parameters k1,k2,p1,p2[,k3[,k4,k5,k6[,s1,s2,s3,s4]]] in\n> + * the model.\n> + *\n> + * \\return A negative number on error, 0 otherwise\n> + */\n> +int Dw100VertexMap::setDewarpParams(const Matrix &cm,\n> + const Span &coeffs)\n> +{\n> + dewarpM_ = cm;\n> + dewarpCoeffs_.fill(0.0);\n> +\n> + if (coeffs.size() != 4 && coeffs.size() != 5 &&\n> + coeffs.size() != 8 && coeffs.size() != 12) {\n> + LOG(Converter, Error)\n> + << \"Dewarp 'coefficients' must have 4, 5, 8 or 12 values\";\n> + dewarpParamsValid_ = false;\n> + return -EINVAL;\n> + }\n> + std::copy(coeffs.begin(), coeffs.end(), dewarpCoeffs_.begin());\n> +\n> + dewarpParamsValid_ = true;\n> + return 0;\n> +}\n> +\n> +/**\n> + * \\fn Dw100VertexMap::dewarpParamsValid()\n> + * \\brief Returns if the dewarp parameters are valid\n> + *\n> + * \\return True if the dewarp parameters are valid, fals otherwise\n\ns/fals/false/\n\nReviewed-by: Kieran Bingham \n\n\n> + */\n> +\n> +/**\n> + * \\fn Dw100VertexMap::setLensDewarpEnable()\n> + * \\brief Enables or disables lens dewarping\n> + * \\param[in] enable Enable or disable lens dewarping\n> + */\n> +\n> +/**\n> + * \\fn Dw100VertexMap::lensDewarpEnable()\n> + * \\brief Returns if lens dewarping is enabled\n> + */\n> +\n> +/**\n> + * \\brief Apply dewarp calculation to a point\n> + * \\param p The point to dewarp\n> + *\n> + * Applies the dewarp transformation to point \\a p according to the commonly\n> + * used dewarp model. See\n> + * https://docs.opencv.org/4.12.0/d9/d0c/group__calib3d.html for further details\n> + * on the model.\n> + *\n> + * \\return The dewarped point\n> + */\n> +Vector2d Dw100VertexMap::dewarpPoint(const Vector2d &p)\n> +{\n> + double x, y;\n> + double k1 = dewarpCoeffs_[0];\n> + double k2 = dewarpCoeffs_[1];\n> + double p1 = dewarpCoeffs_[2];\n> + double p2 = dewarpCoeffs_[3];\n> + double k3 = dewarpCoeffs_[4];\n> + double k4 = dewarpCoeffs_[5];\n> + double k5 = dewarpCoeffs_[6];\n> + double k6 = dewarpCoeffs_[7];\n> + double s1 = dewarpCoeffs_[8];\n> + double s2 = dewarpCoeffs_[9];\n> + double s3 = dewarpCoeffs_[10];\n> + double s4 = dewarpCoeffs_[11];\n> +\n> + y = (p.y() - dewarpM_[1][2]) / dewarpM_[1][1];\n> + x = (p.x() - dewarpM_[0][2] - y * dewarpM_[0][1]) / dewarpM_[0][0];\n> +\n> + double r2 = x * x + y * y;\n> + double d = (1 + k1 * r2 + k2 * r2 * r2 + k3 * r2 * r2 * r2) /\n> + (1 + k4 * r2 + k5 * r2 * r2 + k6 * r2 * r2 * r2);\n> + x = x * d + 2 * p1 * x * y + p2 * (r2 + 2 * x * x) + s1 * r2 + s2 * r2 * r2;\n> + y = y * d + 2 * p2 * x * y + p1 * (r2 + 2 * y * y) + s3 * r2 + s4 * r2 * r2;\n> +\n> + return { { x * dewarpM_[0][0] + y * dewarpM_[0][1] + dewarpM_[0][2],\n> + y * dewarpM_[1][1] + dewarpM_[1][2] } };\n> +}\n> +\n> } /* namespace libcamera */\n> -- \n> 2.51.0\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 5CED6C0F2A\n\tfor ;\n\tTue, 25 Nov 2025 17:46:53 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 9B2AF60A9E;\n\tTue, 25 Nov 2025 18:46:52 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 1A9B4609D8\n\tfor ;\n\tTue, 25 Nov 2025 18:46:51 +0100 (CET)","from pendragon.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust6594.18-1.cable.virginm.net [86.31.185.195])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id CBB8443;\n\tTue, 25 Nov 2025 18:44:41 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"APIhVSXM\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1764092681;\n\tbh=aZINnGX8g4jgmlPkXDOAINfGihHSZ4GIyMnR11QCGYk=;\n\th=In-Reply-To:References:Subject:From:Cc:To:Date:From;\n\tb=APIhVSXM1zwpn1Wn1u9OG2ATDANn/RFvdwYUFYgM2H5DzgqpxeAw3Qtzvi2xauKGj\n\t4UJPVtmUGwv9gOxCPZ9cRyjzyhy0xK0LHCKrJt1CdQDRpjuPcY6Pu3AGwKTw7e2eFd\n\tjyR4iTQBGegnTKdxPyDeVDn3g0LYCcCohZFpGmp8=","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20251125162851.2301793-25-stefan.klug@ideasonboard.com>","References":"<20251125162851.2301793-1-stefan.klug@ideasonboard.com>\n\t<20251125162851.2301793-25-stefan.klug@ideasonboard.com>","Subject":"Re: [PATCH v3 24/29] libcamera: dw100_vertexmap: Implement\n\tparametric dewarping","From":"Kieran Bingham ","Cc":"Stefan Klug ,\n\tPaul Elder ","To":"Stefan Klug ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Tue, 25 Nov 2025 17:46:48 +0000","Message-ID":"<176409280821.567526.12504756477774187335@ping.linuxembedded.co.uk>","User-Agent":"alot/0.9.1","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]