[{"id":4078,"web_url":"https://patchwork.libcamera.org/comment/4078/","msgid":"<20200318154109.GB24538@pendragon.ideasonboard.com>","date":"2020-03-18T15:41:09","subject":"Re: [libcamera-devel] [PATCH] qcam: saveImageAs: Set image quality\n\texplicitly","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"Hi Kieran,\n\nThank you for the patch.\n\nOn Wed, Mar 18, 2020 at 03:13:36PM +0000, Kieran Bingham wrote:\n> The QImageWriter defines a method to set the output image quality.\n> Explicitly set it to 95 to override any defaults.\n\nYou could add, although it's a Qt implementation detail, that by default\nthe JPEG image handler uses a quality of 75, which isn't considered high\nenough ?\n\n> Signed-off-by: Kieran Bingham \n\nReviewed-by: Laurent Pinchart \n\n> ---\n> src/qcam/main_window.cpp | 1 +\n> 1 file changed, 1 insertion(+)\n> \n> diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp\n> index ae1760dfd647..1869fdfc8679 100644\n> --- a/src/qcam/main_window.cpp\n> +++ b/src/qcam/main_window.cpp\n> @@ -360,6 +360,7 @@ void MainWindow::saveImageAs()\n> \t\treturn;\n> \n> \tQImageWriter writer(filename);\n> +\twriter.setQuality(95);\n> \twriter.write(image);\n> }\n>","headers":{"Return-Path":"","Received":["from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id D2B2860418\n\tfor ;\n\tWed, 18 Mar 2020 16:41:14 +0100 (CET)","from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi\n\t[81.175.216.236])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 3D1FAF9;\n\tWed, 18 Mar 2020 16:41:14 +0100 (CET)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1584546074;\n\tbh=GAsj1+MRGZyLxVC9ZX10GD+hbAvsqSrExm0w0hdMSJg=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=TDvCGve1oAfXIFwWeU+Xnc8c9NRkcpUFcx1wl461IR3CIK2C7GPWpLaVGPYyz5kmW\n\tA2p18OdyKyzkFl1LDnUvMMLEXRvcKiftU7J4LnLLFzzgB69nHk130sYr2sNkiadzf5\n\tbWjzORzhC/elUMk84FTLWL3Z+xd9r7KQH6I5X/0U=","Date":"Wed, 18 Mar 2020 17:41:09 +0200","From":"Laurent Pinchart ","To":"Kieran Bingham ","Cc":"libcamera devel ","Message-ID":"<20200318154109.GB24538@pendragon.ideasonboard.com>","References":"<20200318151336.11829-1-kieran.bingham@ideasonboard.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","In-Reply-To":"<20200318151336.11829-1-kieran.bingham@ideasonboard.com>","User-Agent":"Mutt/1.10.1 (2018-07-13)","Subject":"Re: [libcamera-devel] [PATCH] qcam: saveImageAs: Set image quality\n\texplicitly","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","X-List-Received-Date":"Wed, 18 Mar 2020 15:41:15 -0000"}},{"id":4093,"web_url":"https://patchwork.libcamera.org/comment/4093/","msgid":"<2d938399-47f2-f70d-eef2-9d2a3f155b08@ideasonboard.com>","date":"2020-03-19T12:32:38","subject":"Re: [libcamera-devel] [PATCH] qcam: saveImageAs: Set image quality\n\texplicitly","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Hi Laurent,\n\nOn 18/03/2020 15:41, Laurent Pinchart wrote:\n> Hi Kieran,\n> \n> Thank you for the patch.\n> \n> On Wed, Mar 18, 2020 at 03:13:36PM +0000, Kieran Bingham wrote:\n>> The QImageWriter defines a method to set the output image quality.\n>> Explicitly set it to 95 to override any defaults.\n> \n> You could add, although it's a Qt implementation detail, that by default\n> the JPEG image handler uses a quality of 75, which isn't considered high\n> enough ?\n\n\nIndeed, some element of 'ringing' has been observed in the output\nimages, so I have increased the quality level.\n\nThank you for determining the default setting, I hadn't identified what\nthe QT5 default was. I assumed I could get Qt to tell me, but the\n.quality() method returns -1 for me :-(\n\n\nI can update the commit message to:\n\n\"\nThe QImageWriter defaults to an image quality value of 75 which can lead\nto perceivable visual artefacts.\n\nImprove the quality of the output by explicitly setting the image\nquality to 95.\n\"\n\n\n>> Signed-off-by: Kieran Bingham \n> \n> Reviewed-by: Laurent Pinchart \n> \n>> ---\n>> src/qcam/main_window.cpp | 1 +\n>> 1 file changed, 1 insertion(+)\n>>\n>> diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp\n>> index ae1760dfd647..1869fdfc8679 100644\n>> --- a/src/qcam/main_window.cpp\n>> +++ b/src/qcam/main_window.cpp\n>> @@ -360,6 +360,7 @@ void MainWindow::saveImageAs()\n>> \t\treturn;\n>> \n>> \tQImageWriter writer(filename);\n>> +\twriter.setQuality(95);\n>> \twriter.write(image);\n>> }\n>> \n>","headers":{"Return-Path":"","Received":["from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 9A741629AC\n\tfor ;\n\tThu, 19 Mar 2020 13:32:41 +0100 (CET)","from [192.168.0.20]\n\t(cpc89242-aztw30-2-0-cust488.18-1.cable.virginm.net [86.31.129.233])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 00821A53;\n\tThu, 19 Mar 2020 13:32:40 +0100 (CET)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1584621161;\n\tbh=OADOIA9uq0G+HxHbVY4izCjJJqn0xDdj+PEvUx730zw=;\n\th=Reply-To:Subject:To:Cc:References:From:Date:In-Reply-To:From;\n\tb=nZDYq+1XPhq/FqkAh+3N7ORa64ZsO3il7GTJKMjBMgg3Z/N1VTXjTuPQU1gxZYe5t\n\tzTNlvNANUJd3wdbfxL1NqmBPA/PzexDph06qBUZpil4G/WbBpeG/6AYNqS6+M6rbEm\n\t+mSdC1jGbA93vRS2SPiqn35uIUI5xkpizp0AbjfQ=","Reply-To":"kieran.bingham@ideasonboard.com","To":"Laurent Pinchart ","Cc":"libcamera devel ","References":"<20200318151336.11829-1-kieran.bingham@ideasonboard.com>\n\t<20200318154109.GB24538@pendragon.ideasonboard.com>","From":"Kieran Bingham ","Openpgp":"preference=signencrypt","Autocrypt":"addr=kieran.bingham@ideasonboard.com; keydata=\n\tmQINBFYE/WYBEACs1PwjMD9rgCu1hlIiUA1AXR4rv2v+BCLUq//vrX5S5bjzxKAryRf0uHat\n\tV/zwz6hiDrZuHUACDB7X8OaQcwhLaVlq6byfoBr25+hbZG7G3+5EUl9cQ7dQEdvNj6V6y/SC\n\trRanWfelwQThCHckbobWiQJfK9n7rYNcPMq9B8e9F020LFH7Kj6YmO95ewJGgLm+idg1Kb3C\n\tpotzWkXc1xmPzcQ1fvQMOfMwdS+4SNw4rY9f07Xb2K99rjMwZVDgESKIzhsDB5GY465sCsiQ\n\tcSAZRxqE49RTBq2+EQsbrQpIc8XiffAB8qexh5/QPzCmR4kJgCGeHIXBtgRj+nIkCJPZvZtf\n\tKr2EAbc6tgg6DkAEHJb+1okosV09+0+TXywYvtEop/WUOWQ+zo+Y/OBd+8Ptgt1pDRyOBzL8\n\tRXa8ZqRf0Mwg75D+dKntZeJHzPRJyrlfQokngAAs4PaFt6UfS+ypMAF37T6CeDArQC41V3ko\n\tlPn1yMsVD0p+6i3DPvA/GPIksDC4owjnzVX9kM8Zc5Cx+XoAN0w5Eqo4t6qEVbuettxx55gq\n\t8K8FieAjgjMSxngo/HST8TpFeqI5nVeq0/lqtBRQKumuIqDg+Bkr4L1V/PSB6XgQcOdhtd36\n\tOe9X9dXB8YSNt7VjOcO7BTmFn/Z8r92mSAfHXpb07YJWJosQOQARAQABtDBLaWVyYW4gQmlu\n\tZ2hhbSA8a2llcmFuLmJpbmdoYW1AaWRlYXNvbmJvYXJkLmNvbT6JAlcEEwEKAEECGwMFCwkI\n\tBwIGFQgJCgsCBBYCAwECHgECF4ACGQEWIQSQLdeYP70o/eNy1HqhHkZyEKRh/QUCXWTtygUJ\n\tCyJXZAAKCRChHkZyEKRh/f8dEACTDsbLN2nioNZMwyLuQRUAFcXNolDX48xcUXsWS2QjxaPm\n\tVsJx8Uy8aYkS85mdPBh0C83OovQR/OVbr8AxhGvYqBs3nQvbWuTl/+4od7DfK2VZOoKBAu5S\n\tQK2FYuUcikDqYcFWJ8DQnubxfE8dvzojHEkXw0sA4igINHDDFX3HJGZtLio+WpEFQtCbfTAG\n\tYZslasz1YZRbwEdSsmO3/kqy5eMnczlm8a21A3fKUo3g8oAZEFM+f4DUNzqIltg31OAB/kZS\n\tenKZQ/SWC8PmLg/ZXBrReYakxXtkP6w3FwMlzOlhGxqhIRNiAJfXJBaRhuUWzPOpEDE9q5YJ\n\tBmqQL2WJm1VSNNVxbXJHpaWMH1sA2R00vmvRrPXGwyIO0IPYeUYQa3gsy6k+En/aMQJd27dp\n\taScf9am9PFICPY5T4ppneeJLif2lyLojo0mcHOV+uyrds9XkLpp14GfTkeKPdPMrLLTsHRfH\n\tfA4I4OBpRrEPiGIZB/0im98MkGY/Mu6qxeZmYLCcgD6qz4idOvfgVOrNh+aA8HzIVR+RMW8H\n\tQGBN9f0E3kfwxuhl3omo6V7lDw8XOdmuWZNC9zPq1UfryVHANYbLGz9KJ4Aw6M+OgBC2JpkD\n\thXMdHUkC+d20dwXrwHTlrJi1YNp6rBc+xald3wsUPOZ5z8moTHUX/uPA/qhGsbkCDQRWBP1m\n\tARAAzijkb+Sau4hAncr1JjOY+KyFEdUNxRy+hqTJdJfaYihxyaj0Ee0P0zEi35CbE6lgU0Uz\n\ttih9fiUbSV3wfsWqg1Ut3/5rTKu7kLFp15kF7eqvV4uezXRD3Qu4yjv/rMmEJbbD4cTvGCYI\n\td6MDC417f7vK3hCbCVIZSp3GXxyC1LU+UQr3fFcOyCwmP9vDUR9JV0BSqHHxRDdpUXE26Dk6\n\tmhf0V1YkspE5St814ETXpEus2urZE5yJIUROlWPIL+hm3NEWfAP06vsQUyLvr/GtbOT79vXl\n\tEn1aulcYyu20dRRxhkQ6iILaURcxIAVJJKPi8dsoMnS8pB0QW12AHWuirPF0g6DiuUfPmrA5\n\tPKe56IGlpkjc8cO51lIxHkWTpCMWigRdPDexKX+Sb+W9QWK/0JjIc4t3KBaiG8O4yRX8ml2R\n\t+rxfAVKM6V769P/hWoRGdgUMgYHFpHGSgEt80OKK5HeUPy2cngDUXzwrqiM5Sz6Od0qw5pCk\n\tNlXqI0W/who0iSVM+8+RmyY0OEkxEcci7rRLsGnM15B5PjLJjh1f2ULYkv8s4SnDwMZ/kE04\n\t/UqCMK/KnX8pwXEMCjz0h6qWNpGwJ0/tYIgQJZh6bqkvBrDogAvuhf60Sogw+mH8b+PBlx1L\n\toeTK396wc+4c3BfiC6pNtUS5GpsPMMjYMk7kVvEAEQEAAYkCPAQYAQoAJgIbDBYhBJAt15g/\n\tvSj943LUeqEeRnIQpGH9BQJdizzIBQkLSKZiAAoJEKEeRnIQpGH9eYgQAJpjaWNgqNOnMTmD\n\tMJggbwjIotypzIXfhHNCeTkG7+qCDlSaBPclcPGYrTwCt0YWPU2TgGgJrVhYT20ierN8LUvj\n\t6qOPTd+Uk7NFzL65qkh80ZKNBFddx1AabQpSVQKbdcLb8OFs85kuSvFdgqZwgxA1vl4TFhNz\n\tPZ79NAmXLackAx3sOVFhk4WQaKRshCB7cSl+RIng5S/ThOBlwNlcKG7j7W2MC06BlTbdEkUp\n\tECzuuRBv8wX4OQl+hbWbB/VKIx5HKlLu1eypen/5lNVzSqMMIYkkZcjV2SWQyUGxSwq0O/sx\n\tS0A8/atCHUXOboUsn54qdxrVDaK+6jIAuo8JiRWctP16KjzUM7MO0/+4zllM8EY57rXrj48j\n\tsbEYX0YQnzaj+jO6kJtoZsIaYR7rMMq9aUAjyiaEZpmP1qF/2sYenDx0Fg2BSlLvLvXM0vU8\n\tpQk3kgDu7kb/7PRYrZvBsr21EIQoIjXbZxDz/o7z95frkP71EaICttZ6k9q5oxxA5WC6sTXc\n\tMW8zs8avFNuA9VpXt0YupJd2ijtZy2mpZNG02fFVXhIn4G807G7+9mhuC4XG5rKlBBUXTvPU\n\tAfYnB4JBDLmLzBFavQfvonSfbitgXwCG3vS+9HEwAjU30Bar1PEOmIbiAoMzuKeRm2LVpmq4\n\tWZw01QYHU/GUV/zHJSFk","Organization":"Ideas on Board","Message-ID":"<2d938399-47f2-f70d-eef2-9d2a3f155b08@ideasonboard.com>","Date":"Thu, 19 Mar 2020 12:32:38 +0000","User-Agent":"Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101\n\tThunderbird/60.9.1","MIME-Version":"1.0","In-Reply-To":"<20200318154109.GB24538@pendragon.ideasonboard.com>","Content-Type":"text/plain; charset=utf-8","Content-Language":"en-GB","Content-Transfer-Encoding":"8bit","Subject":"Re: [libcamera-devel] [PATCH] qcam: saveImageAs: Set image quality\n\texplicitly","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","X-List-Received-Date":"Thu, 19 Mar 2020 12:32:41 -0000"}},{"id":4097,"web_url":"https://patchwork.libcamera.org/comment/4097/","msgid":"<20200319131103.GD4872@pendragon.ideasonboard.com>","date":"2020-03-19T13:11:03","subject":"Re: [libcamera-devel] [PATCH] qcam: saveImageAs: Set image quality\n\texplicitly","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"Hi Kieran,\n\nOn Thu, Mar 19, 2020 at 12:32:38PM +0000, Kieran Bingham wrote:\n> On 18/03/2020 15:41, Laurent Pinchart wrote:\n> > On Wed, Mar 18, 2020 at 03:13:36PM +0000, Kieran Bingham wrote:\n> >> The QImageWriter defines a method to set the output image quality.\n> >> Explicitly set it to 95 to override any defaults.\n> > \n> > You could add, although it's a Qt implementation detail, that by default\n> > the JPEG image handler uses a quality of 75, which isn't considered high\n> > enough ?\n> \n> Indeed, some element of 'ringing' has been observed in the output\n> images, so I have increased the quality level.\n> \n> Thank you for determining the default setting, I hadn't identified what\n> the QT5 default was. I assumed I could get Qt to tell me, but the\n> .quality() method returns -1 for me :-(\n> \n> I can update the commit message to:\n> \n> \"\n> The QImageWriter defaults to an image quality value of 75 which can lead\n> to perceivable visual artefacts.\n> \n> Improve the quality of the output by explicitly setting the image\n> quality to 95.\n> \"\n\nWorks for me.\n\n> >> Signed-off-by: Kieran Bingham \n> > \n> > Reviewed-by: Laurent Pinchart \n> > \n> >> ---\n> >> src/qcam/main_window.cpp | 1 +\n> >> 1 file changed, 1 insertion(+)\n> >>\n> >> diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp\n> >> index ae1760dfd647..1869fdfc8679 100644\n> >> --- a/src/qcam/main_window.cpp\n> >> +++ b/src/qcam/main_window.cpp\n> >> @@ -360,6 +360,7 @@ void MainWindow::saveImageAs()\n> >> \t\treturn;\n> >> \n> >> \tQImageWriter writer(filename);\n> >> +\twriter.setQuality(95);\n> >> \twriter.write(image);\n> >> }\n> >>","headers":{"Return-Path":"","Received":["from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id B877F60418\n\tfor ;\n\tThu, 19 Mar 2020 14:11:09 +0100 (CET)","from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi\n\t[81.175.216.236])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 2591FA53;\n\tThu, 19 Mar 2020 14:11:09 +0100 (CET)"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1584623469;\n\tbh=sR1E2nW6fkh14r6kztf7uL9wnF5kiOO2IuAn3xI9yZI=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=OtrMWuEkl6QLwi4s6Q3bc2vQMMrUOqFpxgj1hh2FKcR5yeWYwoqnIW4RWXXsd1neq\n\t/Mjx76h2B99Sr810M+K28GQ7UJ3UfhvFz/lSda5jxPZP+CIiimDqq3JOROf8/Gcxvt\n\t/ca//zL2nEaJwKOPV7hL9nOYfifl6vqG8z0E9Zsg=","Date":"Thu, 19 Mar 2020 15:11:03 +0200","From":"Laurent Pinchart ","To":"Kieran Bingham ","Cc":"libcamera devel ","Message-ID":"<20200319131103.GD4872@pendragon.ideasonboard.com>","References":"<20200318151336.11829-1-kieran.bingham@ideasonboard.com>\n\t<20200318154109.GB24538@pendragon.ideasonboard.com>\n\t<2d938399-47f2-f70d-eef2-9d2a3f155b08@ideasonboard.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","In-Reply-To":"<2d938399-47f2-f70d-eef2-9d2a3f155b08@ideasonboard.com>","User-Agent":"Mutt/1.10.1 (2018-07-13)","Subject":"Re: [libcamera-devel] [PATCH] qcam: saveImageAs: Set image quality\n\texplicitly","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","X-List-Received-Date":"Thu, 19 Mar 2020 13:11:09 -0000"}}]