[{"id":14128,"web_url":"https://patchwork.libcamera.org/comment/14128/","msgid":"","date":"2020-12-08T10:09:39","subject":"Re: [libcamera-devel] [PATCH v2 4/6] src: ipa: raspberrypi: Compute\n\tinverse of piecewise linear function","submitter":{"id":34,"url":"https://patchwork.libcamera.org/api/people/34/","name":"Naushir Patuck","email":"naush@raspberrypi.com"},"content":"Hi David,\n\nThank you for your patch.\n\n\nOn Mon, 7 Dec 2020 at 18:02, David Plowman \nwrote:\n\n> Add a method to the piecewise linear function (Pwl) class to compute\n> the inverse of a given Pwl. If the input function is non-monotonic we\n> can only produce a best effort \"pseudo\" inverse, and we signal this to\n> the caller.\n>\n> Signed-off-by: David Plowman \n>\n\nReviewed-by: Naushir Patuck \n\n\n> ---\n> src/ipa/raspberrypi/controller/pwl.cpp | 27 ++++++++++++++++++++++++++\n> src/ipa/raspberrypi/controller/pwl.hpp | 3 +++\n> 2 files changed, 30 insertions(+)\n>\n> diff --git a/src/ipa/raspberrypi/controller/pwl.cpp\n> b/src/ipa/raspberrypi/controller/pwl.cpp\n> index aa134a1f..70206418 100644\n> --- a/src/ipa/raspberrypi/controller/pwl.cpp\n> +++ b/src/ipa/raspberrypi/controller/pwl.cpp\n> @@ -114,6 +114,33 @@ Pwl::PerpType Pwl::Invert(Point const &xy, Point\n> &perp, int &span,\n> return PerpType::None;\n> }\n>\n> +Pwl Pwl::Inverse(bool *true_inverse, const double eps) const\n> +{\n> + bool appended = false, prepended = false, neither = false;\n> + Pwl inverse;\n> +\n> + for (Point const &p : points_) {\n> + if (inverse.Empty())\n> + inverse.Append(p.y, p.x, eps);\n> + else if (p.y > inverse.points_.back().x - eps) {\n> + inverse.Append(p.y, p.x, eps);\n> + appended = true;\n> + } else if (p.y < inverse.points_.front().x + eps) {\n> + inverse.Prepend(p.y, p.x, eps);\n> + prepended = true;\n> + } else\n> + neither = true;\n> + }\n> +\n> + // This is not a proper inverse if we found ourselves putting\n> points\n> + // onto both ends of the inverse, or if there were points that\n> couldn't\n> + // go on either.\n> + if (true_inverse)\n> + *true_inverse = !(neither || (appended && prepended));\n> +\n> + return inverse;\n> +}\n> +\n> Pwl Pwl::Compose(Pwl const &other, const double eps) const\n> {\n> double this_x = points_[0].x, this_y = points_[0].y;\n> diff --git a/src/ipa/raspberrypi/controller/pwl.hpp\n> b/src/ipa/raspberrypi/controller/pwl.hpp\n> index 4f168551..484672f6 100644\n> --- a/src/ipa/raspberrypi/controller/pwl.hpp\n> +++ b/src/ipa/raspberrypi/controller/pwl.hpp\n> @@ -80,6 +80,9 @@ public:\n> };\n> PerpType Invert(Point const &xy, Point &perp, int &span,\n> const double eps = 1e-6) const;\n> + // Compute the inverse function. Indicate if it is a proper (true)\n> + // inverse, or only a best effort (e.g. input was non-monotonic).\n> + Pwl Inverse(bool *true_inverse = nullptr, const double eps = 1e-6)\n> const;\n> // Compose two Pwls together, doing \"this\" first and \"other\" after.\n> Pwl Compose(Pwl const &other, const double eps = 1e-6) const;\n> // Apply function to (x,y) values at every control point.\n> --\n> 2.20.1\n>\n> _______________________________________________\n> libcamera-devel mailing list\n> libcamera-devel@lists.libcamera.org\n> https://lists.libcamera.org/listinfo/libcamera-devel\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 DBC02BDB1F\n\tfor ;\n\tTue, 8 Dec 2020 10:10:00 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 9413B67E6E;\n\tTue, 8 Dec 2020 11:10:00 +0100 (CET)","from mail-lf1-x12e.google.com (mail-lf1-x12e.google.com\n\t[IPv6:2a00:1450:4864:20::12e])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 12354635F2\n\tfor ;\n\tTue, 8 Dec 2020 11:09:59 +0100 (CET)","by mail-lf1-x12e.google.com with SMTP id y19so10110376lfa.13\n\tfor ;\n\tTue, 08 Dec 2020 02:09:59 -0800 (PST)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (2048-bit key;\n\tunprotected) header.d=raspberrypi.com header.i=@raspberrypi.com\n\theader.b=\"qVIMibtj\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=raspberrypi.com; s=google;\n\th=mime-version:references:in-reply-to:from:date:message-id:subject:to\n\t:cc; bh=QuwBIo6PCsUknyY+EW2wWTj6N6OCgDDQVxsSMcOexTY=;\n\tb=qVIMibtj+goqZraVi4HmSb0YOzaYRHrMmQYVZmNhASAak9erAhYOsKl7TtyATI5jOa\n\tjVlWbvx625aT9zvEb2g6M9Eeedto3VktL1O9lUbD9mwx1L9NS6hT67U0MKPZ+wakqAs5\n\ta4T5LmUMhk8mehp5y5XqILyDd88i5U/Wi/zQyzBvQafwIViYxH4y49zsqVCvx6bJqduf\n\ty6dxBX0scTAV2vE3hzzww1hQ7BdbZIv0JubAgbUGMrjqLQ67B3xrD3FOW4FS3ne+qOS0\n\t/IG50h3xEb0mkFsS1rislJeGfZKdVyZtNn0IbVc1cpj051ABkfinmTQ7uWyCoTQC4+zV\n\t7NJw==","X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20161025;\n\th=x-gm-message-state:mime-version:references:in-reply-to:from:date\n\t:message-id:subject:to:cc;\n\tbh=QuwBIo6PCsUknyY+EW2wWTj6N6OCgDDQVxsSMcOexTY=;\n\tb=olSYlgeqqeueYWzYJ5QMnfTh0QRsvjncQf/KIlywbK16YzRlaF6Qox681snQHkcUUN\n\tY/K2v16ohHibn5/eWVRhZrpfcksKwYVUE5Co1nivWMGH6HmhY/N8H/P21p+0dG7CBWks\n\tnzqB8fOFlK1rbTT/WDe08SJ2MK+eHD+Tx8R7nTt6y9uowR54VlvmSzq6ZUXOnFyU2O2k\n\t6oo4jN7CSIrI6ee/w3nEHJHibcNRTCEbKCG1IP3mQpSxnECA9JSGZ2o6BODATxtCxQL5\n\tiHikFHh1/lRPD4TW9pUKUsUOkk55ThfvjHp2VSdHzk0t1sz+GUMrHc6lKaCNy44sc7G3\n\tlEqA==","X-Gm-Message-State":"AOAM531dife8HEL7RlsIA4bpz2zig850XnpXtCo3TL8qTHz9XT1Tt4EL\n\tPhSigNb9wjqrXJlCLKPqN0R9Cg0sh7XgH+n7fqQ2SkWZpE4=","X-Google-Smtp-Source":"ABdhPJxk9UqpRYVYXG4H87C6B2RGz3xLJKyU2yXIwxduruwRcb+DomWmFNOujX2Q7c6YQkC8mXADPlQyaNFQ0vOPwSc=","X-Received":"by 2002:a05:6512:3047:: with SMTP id\n\tb7mr9419927lfb.210.1607422198526; \n\tTue, 08 Dec 2020 02:09:58 -0800 (PST)","MIME-Version":"1.0","References":"<20201207180121.6374-1-david.plowman@raspberrypi.com>\n\t<20201207180121.6374-5-david.plowman@raspberrypi.com>","In-Reply-To":"<20201207180121.6374-5-david.plowman@raspberrypi.com>","From":"Naushir Patuck ","Date":"Tue, 8 Dec 2020 10:09:39 +0000","Message-ID":"","To":"David Plowman ","Subject":"Re: [libcamera-devel] [PATCH v2 4/6] src: ipa: raspberrypi: Compute\n\tinverse of piecewise linear function","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","Cc":"libcamera devel ","Content-Type":"multipart/mixed;\n\tboundary=\"===============6483950664657031655==\"","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":14139,"web_url":"https://patchwork.libcamera.org/comment/14139/","msgid":"","date":"2020-12-08T11:46:02","subject":"Re: [libcamera-devel] [PATCH v2 4/6] src: ipa: raspberrypi: Compute\n\tinverse of piecewise linear function","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"Hi David,\n\nThank you for the patch.\n\nOn Mon, Dec 07, 2020 at 06:01:19PM +0000, David Plowman wrote:\n> Add a method to the piecewise linear function (Pwl) class to compute\n> the inverse of a given Pwl. If the input function is non-monotonic we\n> can only produce a best effort \"pseudo\" inverse, and we signal this to\n> the caller.\n> \n> Signed-off-by: David Plowman \n> ---\n> src/ipa/raspberrypi/controller/pwl.cpp | 27 ++++++++++++++++++++++++++\n> src/ipa/raspberrypi/controller/pwl.hpp | 3 +++\n> 2 files changed, 30 insertions(+)\n> \n> diff --git a/src/ipa/raspberrypi/controller/pwl.cpp b/src/ipa/raspberrypi/controller/pwl.cpp\n> index aa134a1f..70206418 100644\n> --- a/src/ipa/raspberrypi/controller/pwl.cpp\n> +++ b/src/ipa/raspberrypi/controller/pwl.cpp\n> @@ -114,6 +114,33 @@ Pwl::PerpType Pwl::Invert(Point const &xy, Point &perp, int &span,\n> \treturn PerpType::None;\n> }\n> \n> +Pwl Pwl::Inverse(bool *true_inverse, const double eps) const\n> +{\n> +\tbool appended = false, prepended = false, neither = false;\n> +\tPwl inverse;\n> +\n> +\tfor (Point const &p : points_) {\n> +\t\tif (inverse.Empty())\n> +\t\t\tinverse.Append(p.y, p.x, eps);\n> +\t\telse if (p.y > inverse.points_.back().x - eps) {\n\nShouldn't this be + eps (and - eps below), based on Pwl::Append() and\nPwm::Prepend() ?\n\nReviewed-by: Laurent Pinchart \n\n> +\t\t\tinverse.Append(p.y, p.x, eps);\n> +\t\t\tappended = true;\n> +\t\t} else if (p.y < inverse.points_.front().x + eps) {\n> +\t\t\tinverse.Prepend(p.y, p.x, eps);\n> +\t\t\tprepended = true;\n> +\t\t} else\n> +\t\t\tneither = true;\n> +\t}\n> +\n> +\t// This is not a proper inverse if we found ourselves putting points\n> +\t// onto both ends of the inverse, or if there were points that couldn't\n> +\t// go on either.\n> +\tif (true_inverse)\n> +\t\t*true_inverse = !(neither || (appended && prepended));\n> +\n> +\treturn inverse;\n> +}\n> +\n> Pwl Pwl::Compose(Pwl const &other, const double eps) const\n> {\n> \tdouble this_x = points_[0].x, this_y = points_[0].y;\n> diff --git a/src/ipa/raspberrypi/controller/pwl.hpp b/src/ipa/raspberrypi/controller/pwl.hpp\n> index 4f168551..484672f6 100644\n> --- a/src/ipa/raspberrypi/controller/pwl.hpp\n> +++ b/src/ipa/raspberrypi/controller/pwl.hpp\n> @@ -80,6 +80,9 @@ public:\n> \t};\n> \tPerpType Invert(Point const &xy, Point &perp, int &span,\n> \t\t\tconst double eps = 1e-6) const;\n> +\t// Compute the inverse function. Indicate if it is a proper (true)\n> +\t// inverse, or only a best effort (e.g. input was non-monotonic).\n> +\tPwl Inverse(bool *true_inverse = nullptr, const double eps = 1e-6) const;\n> \t// Compose two Pwls together, doing \"this\" first and \"other\" after.\n> \tPwl Compose(Pwl const &other, const double eps = 1e-6) const;\n> \t// Apply function to (x,y) values at every control point.","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 BA5ADBDB20\n\tfor ;\n\tTue, 8 Dec 2020 11:46:07 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 3B99867E6D;\n\tTue, 8 Dec 2020 12:46:07 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id DBEF6600FF\n\tfor ;\n\tTue, 8 Dec 2020 12:46:05 +0100 (CET)","from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi\n\t[62.78.145.57])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 538BFDD;\n\tTue, 8 Dec 2020 12:46:05 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"mMbfJR4X\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1607427965;\n\tbh=EA3m0/vCCS1uSOz/xH+JRGoyQt+s0TOeboeC8ehusyY=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=mMbfJR4X0v1V+QFIBb1Tg1oCdD1nCzAb6zIYJJ6in3dNHK4TobEDkgiPAfYDEvkSl\n\tu4KkBcAAjR79wapmkbwayDxPe49crGJJOPU5109PB6gIE3e57p91eYEAsv8EnMEXwX\n\tmwM/wz96KygOKjnteI/WVrINYStf5ER8OTaCX/x4=","Date":"Tue, 8 Dec 2020 13:46:02 +0200","From":"Laurent Pinchart ","To":"David Plowman ","Message-ID":"","References":"<20201207180121.6374-1-david.plowman@raspberrypi.com>\n\t<20201207180121.6374-5-david.plowman@raspberrypi.com>","MIME-Version":"1.0","Content-Disposition":"inline","In-Reply-To":"<20201207180121.6374-5-david.plowman@raspberrypi.com>","Subject":"Re: [libcamera-devel] [PATCH v2 4/6] src: ipa: raspberrypi: Compute\n\tinverse of piecewise linear function","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","Cc":"libcamera-devel@lists.libcamera.org","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":14143,"web_url":"https://patchwork.libcamera.org/comment/14143/","msgid":"","date":"2020-12-08T12:05:25","subject":"Re: [libcamera-devel] [PATCH v2 4/6] src: ipa: raspberrypi: Compute\n\tinverse of piecewise linear function","submitter":{"id":42,"url":"https://patchwork.libcamera.org/api/people/42/","name":"David Plowman","email":"david.plowman@raspberrypi.com"},"content":"Hi Laurent\n\nThanks for the review.\n\nOn Tue, 8 Dec 2020 at 11:46, Laurent Pinchart\n wrote:\n>\n> Hi David,\n>\n> Thank you for the patch.\n>\n> On Mon, Dec 07, 2020 at 06:01:19PM +0000, David Plowman wrote:\n> > Add a method to the piecewise linear function (Pwl) class to compute\n> > the inverse of a given Pwl. If the input function is non-monotonic we\n> > can only produce a best effort \"pseudo\" inverse, and we signal this to\n> > the caller.\n> >\n> > Signed-off-by: David Plowman \n> > ---\n> > src/ipa/raspberrypi/controller/pwl.cpp | 27 ++++++++++++++++++++++++++\n> > src/ipa/raspberrypi/controller/pwl.hpp | 3 +++\n> > 2 files changed, 30 insertions(+)\n> >\n> > diff --git a/src/ipa/raspberrypi/controller/pwl.cpp b/src/ipa/raspberrypi/controller/pwl.cpp\n> > index aa134a1f..70206418 100644\n> > --- a/src/ipa/raspberrypi/controller/pwl.cpp\n> > +++ b/src/ipa/raspberrypi/controller/pwl.cpp\n> > @@ -114,6 +114,33 @@ Pwl::PerpType Pwl::Invert(Point const &xy, Point &perp, int &span,\n> > return PerpType::None;\n> > }\n> >\n> > +Pwl Pwl::Inverse(bool *true_inverse, const double eps) const\n> > +{\n> > + bool appended = false, prepended = false, neither = false;\n> > + Pwl inverse;\n> > +\n> > + for (Point const &p : points_) {\n> > + if (inverse.Empty())\n> > + inverse.Append(p.y, p.x, eps);\n> > + else if (p.y > inverse.points_.back().x - eps) {\n>\n> Shouldn't this be + eps (and - eps below), based on Pwl::Append() and\n> Pwm::Prepend() ?\n\nYes, as always these numerical things are a bit icky. So if I had\n\nelse if (p.y > inverse.points_.back().x + eps) {\n\nthen a point that is eps/2 beyond back().x would end up triggering the\n\"neither\" case, which seems harsh. I guess there's a possibility the\ninput function was constructed with a smaller value for eps. On\nbalance I felt that \"within eps of the end\" was probably good enough\nto accept the point, and either create a new segment, or drop it\nwithout complaint.\n\nThough on reflection I can see an argument for explicitly checking the\n\"within eps of the start/end\" case and then deliberately doing nothing\n(not setting appended/prepended), so I might add that.\n\nThanks\nDavid\n\n>\n> Reviewed-by: Laurent Pinchart \n>\n> > + inverse.Append(p.y, p.x, eps);\n> > + appended = true;\n> > + } else if (p.y < inverse.points_.front().x + eps) {\n> > + inverse.Prepend(p.y, p.x, eps);\n> > + prepended = true;\n> > + } else\n> > + neither = true;\n> > + }\n> > +\n> > + // This is not a proper inverse if we found ourselves putting points\n> > + // onto both ends of the inverse, or if there were points that couldn't\n> > + // go on either.\n> > + if (true_inverse)\n> > + *true_inverse = !(neither || (appended && prepended));\n> > +\n> > + return inverse;\n> > +}\n> > +\n> > Pwl Pwl::Compose(Pwl const &other, const double eps) const\n> > {\n> > double this_x = points_[0].x, this_y = points_[0].y;\n> > diff --git a/src/ipa/raspberrypi/controller/pwl.hpp b/src/ipa/raspberrypi/controller/pwl.hpp\n> > index 4f168551..484672f6 100644\n> > --- a/src/ipa/raspberrypi/controller/pwl.hpp\n> > +++ b/src/ipa/raspberrypi/controller/pwl.hpp\n> > @@ -80,6 +80,9 @@ public:\n> > };\n> > PerpType Invert(Point const &xy, Point &perp, int &span,\n> > const double eps = 1e-6) const;\n> > + // Compute the inverse function. Indicate if it is a proper (true)\n> > + // inverse, or only a best effort (e.g. input was non-monotonic).\n> > + Pwl Inverse(bool *true_inverse = nullptr, const double eps = 1e-6) const;\n> > // Compose two Pwls together, doing \"this\" first and \"other\" after.\n> > Pwl Compose(Pwl const &other, const double eps = 1e-6) const;\n> > // Apply function to (x,y) values at every control point.\n>\n> --\n> Regards,\n>\n> Laurent Pinchart","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 E5AC1BDB20\n\tfor ;\n\tTue, 8 Dec 2020 12:05:39 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 6F19E67E71;\n\tTue, 8 Dec 2020 13:05:39 +0100 (CET)","from mail-oi1-x244.google.com (mail-oi1-x244.google.com\n\t[IPv6:2607:f8b0:4864:20::244])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id E708567E15\n\tfor ;\n\tTue, 8 Dec 2020 13:05:37 +0100 (CET)","by mail-oi1-x244.google.com with SMTP id l200so19114585oig.9\n\tfor ;\n\tTue, 08 Dec 2020 04:05:37 -0800 (PST)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (2048-bit key;\n\tunprotected) header.d=raspberrypi.com header.i=@raspberrypi.com\n\theader.b=\"MMFC6bZ/\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=raspberrypi.com; s=google;\n\th=mime-version:references:in-reply-to:from:date:message-id:subject:to\n\t:cc; bh=UpiCiAxh4k2CCZc+t0PfbHRAa1AoPQ+oNmAZkYkTlgQ=;\n\tb=MMFC6bZ/pKV9UlmkRIBGGHLPwGnArxuBgCPFqU/sBVXeYzYVyta7INtDxNVydT78Kb\n\tfP99yf2KzSrmhLgu0Tc1dgkAAA6Ze+QBvpffT7ou7SVupiKZNcPvcIGDyo5QQea2DSzo\n\tTzhyjKd6fc1Uy2V79RjGmlnSrO3Kb6KZYMBYB5bra2BekSiPm2ayePFQ63wJwsWS3DpZ\n\taQ9JlCdT7g+GGG9IQNPnUd2K6uCx0accY8qmA5cafgmT91vla+H6GT0yrpyz6J0RrXPw\n\tSrTnTgArilqpZK58/mAGspfwJIZtUtzn4h3QdmC8c1pRUGHut+iCBXBrQr93zYHA9ffw\n\tJKmw==","X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20161025;\n\th=x-gm-message-state:mime-version:references:in-reply-to:from:date\n\t:message-id:subject:to:cc;\n\tbh=UpiCiAxh4k2CCZc+t0PfbHRAa1AoPQ+oNmAZkYkTlgQ=;\n\tb=A0Li/yTJuhye0kKHbEchtRJ70K6Canu/nfJuJh4SW082JLDQDKw2KC2VB8QAJaWjJ4\n\twjITVV8gmxV63kV/lyoNYKLFlh810ESfzN1uPVr1shH3oknnjitSCOeRGiGfM9KOQULd\n\tZi8S4r83ZYtGj9cMeFJh/vhrSTa5+sL40Ro7L2Es03FQBiNbJNKjrGkPxJJxglG1XE2B\n\tz7CNi6cdqMAvfRchOHvLL9nyD1h2IRhuYfkl3TeMMw6CwysrEjiupztJvEzCTAP+JJUv\n\t5GescQ53a4Qns5CJXjQcEhNC74ITVd3WDHGRBjl+a+mf3AG9T61FRr5mQKTnnX6PZpnc\n\th/cg==","X-Gm-Message-State":"AOAM533piAq6nZdg4GW9MxH7zzpehheqS/k3Ni7wQMXUBG0VWuCeJP8n\n\tlS9MlDg1yLXH7fkK7uhGgWyyMDw06l0I+PyiTgscMiz/wiXnBA==","X-Google-Smtp-Source":"ABdhPJzCHYOUVBLEVqAD0MngITTpWhjaWEmoWmPEdHsuo2aV/yJoPDiu0DQkScjGA57APwFqA1uyKSbTQHtuqlspH2U=","X-Received":"by 2002:aca:3c3:: with SMTP id 186mr2373448oid.22.1607429136476; \n\tTue, 08 Dec 2020 04:05:36 -0800 (PST)","MIME-Version":"1.0","References":"<20201207180121.6374-1-david.plowman@raspberrypi.com>\n\t<20201207180121.6374-5-david.plowman@raspberrypi.com>\n\t","In-Reply-To":"","From":"David Plowman ","Date":"Tue, 8 Dec 2020 12:05:25 +0000","Message-ID":"","To":"Laurent Pinchart ","Subject":"Re: [libcamera-devel] [PATCH v2 4/6] src: ipa: raspberrypi: Compute\n\tinverse of piecewise linear function","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","Cc":"libcamera devel ","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]