<AWT Dev> Review Request JDK:-8162959 [HiDPI] screenshot artifacts using AWT Robot
Alexandr Scherbatiy
alexandr.scherbatiy at oracle.com
Mon Jan 9 19:38:01 UTC 2017
CGWindowListCreateImage() method which is used to capture a
screenshot on Mac OS X by Robot has imageOption argument which can have
value: kCGWindowImageBestResolution
https://developer.apple.com/reference/coregraphics/1666230-quartz_window_services/window_image_types?language=objc
"When capturing the window, return the best image resolution. The
returned image size may be different than the screen size."
Could this option help to get a high-resolution CGImageRef on HiDPI
display?
Thanks,
Alexandr.
On 12/27/2016 12:14 PM, Prem Balakrishnan wrote:
>
> Hi Alexander,
>
> Please review updated patch,
>
> http://cr.openjdk.java.net/~pkbalakr/8162959/webrev.04/
> <http://cr.openjdk.java.net/%7Epkbalakr/8162959/webrev.04/>
>
> I used wrong bounds while creating images, correct it in this patch.
>
> Regards,
>
> Prem
>
> *From:*Alexander Scherbatiy
> *Sent:* Wednesday, December 14, 2016 5:18 PM
> *To:* Prem Balakrishnan; Sergey Bylokhov; awt-dev at openjdk.java.net;
> Philip Race
> *Subject:* Re: Review Request JDK:-8162959 [HiDPI] screenshot
> artifacts using AWT Robot
>
> On 07/12/16 10:24, Prem Balakrishnan wrote:
>
> Hi Alexander,
>
> Please review updated patch as per review comments.
>
> http://cr.openjdk.java.net/~pkbalakr/8162959/webrev.03/
> <http://cr.openjdk.java.net/%7Epkbalakr/8162959/webrev.03/>
>
> I used a simple app [1] to create a screenshot of a frame on Mac OS X:
> Rectangle rect = frame.getBounds();
> rect.setLocation(frame.getLocationOnScreen());
> BufferedImage img = robot.createScreenCapture(rect);
>
> It takes only bottom right quarter of the frame [2].
>
> Is it possible to use some API that makes a screenshot and returns
> an NSImage on Mac OS X?
> In this case it would be possible to get a high resolution
> representation from the NSImage and return it in the same way as it is
> updated on Windows and Linux.
>
> [1]
> http://cr.openjdk.java.net/~alexsch/8162959/screenshot/RobotScreenshot.java
> <http://cr.openjdk.java.net/%7Ealexsch/8162959/screenshot/RobotScreenshot.java>
> [2]
> http://cr.openjdk.java.net/~alexsch/8162959/screenshot/screenshot.png
> <http://cr.openjdk.java.net/%7Ealexsch/8162959/screenshot/screenshot.png>
>
> Thanks,
> Alexandr.
>
> Regards,
>
> Prem
>
> *From:*Alexandr Scherbatiy
> *Sent:* Monday, November 21, 2016 8:10 PM
> *To:* Prem Balakrishnan; Sergey Bylokhov; awt-dev at openjdk.java.net
> <mailto:awt-dev at openjdk.java.net>; Phil Race
> *Subject:* Re: Review Request JDK:-8162959 [HiDPI] screenshot
> artifacts using AWT Robot
>
> On 11/16/2016 8:46 AM, Prem Balakrishnan wrote:
>
>
> Hi Alexander,
>
> Please review update patch as per review comments.
>
> http://cr.openjdk.java.net/~pkbalakr/8162959/webrev.02/
> <http://cr.openjdk.java.net/%7Epkbalakr/8162959/webrev.02/>
>
> With this patch, Robot.createScreenCapture(Rectangle) method returns a
> scaled down image on the HiDPI display.
>
>
> - The native part on Mac OS X and Linux should be updated as well.
>
> - 416 * Returns BufferedImage for Non-HiDPI display and
> MultiResolutionImage
> 417 * for HiDPI display with two resolution variants.
>
> There should be added an explanation what is the content of the first
> and the second resolution variant.
>
> Thanks,
> Alexandr.
>
>
>
> Regards,
>
> Prem
>
> *From:*Alexandr Scherbatiy
> *Sent:* Thursday, November 03, 2016 4:05 PM
> *To:* Prem Balakrishnan; Sergey Bylokhov; awt-dev at openjdk.java.net
> <mailto:awt-dev at openjdk.java.net>
> *Subject:* Re: Review Request JDK:-8162959 [HiDPI] screenshot
> artifacts using AWT Robot
>
> On 11/2/2016 1:57 PM, Prem Balakrishnan wrote:
>
>
>
> Hi Alexander,
>
> Please review updated patch.
>
> http://cr.openjdk.java.net/~pkbalakr/8162959/webrev.01/
> <http://cr.openjdk.java.net/%7Epkbalakr/8162959/webrev.01/>
>
> Added a new public API “*Image createHiDPIScreenCapture(Rectangle
> screenRect)”.*
>
> Returns an ordinary screenshot(BufferedImage) if the UI scale is 1.
>
> Returns MultiResolutionImage for HiDPI display with two resolution
> variants,
>
> 1.Low Resolution/base image with user input width and height, I have
> used interpolation algorithm for scaling , adapted from JavaFX Robot
> (http://hg.openjdk.java.net/openjfx/9-dev/rt/rev/89a5de54b7dc),
>
> 2.High Resolution image with scaled width and height .
>
> - Please, check that the Robot.createScreenCapture(Rectangle) method
> returns a scaled down image on the HiDPI display
> - Probably existing Java methods can be used for an image scaling.
> For example, there is the Image.getScaledInstance(int width, int
> height, int hints) method.
> Or may be it is better just to create an image with required size
> and draw the high-resolution image into it using a specific scale and
> rendering hints.
>
> Thanks,
> Alexandr.
>
>
>
>
> Regards,
>
> Prem
>
> *From:*Alexander Scherbatiy
> *Sent:* Thursday, October 13, 2016 3:21 PM
> *To:* Prem Balakrishnan; Sergey Bylokhov; awt-dev at openjdk.java.net
> <mailto:awt-dev at openjdk.java.net>
> *Subject:* Re: Review Request JDK:-8162959 [HiDPI] screenshot
> artifacts using AWT Robot
>
> On 06/10/16 15:28, Prem Balakrishnan wrote:
>
> Hi*,*
>
> **
>
> Please review fix for JDK 9,
>
> *Bug:*https://bugs.openjdk.java.net/browse/JDK-8162959
>
> *Webrev:*http://cr.openjdk.java.net/~pkbalakr/8162959/webrev.00/
> <http://cr.openjdk.java.net/%7Epkbalakr/8162959/webrev.00/>
>
> I have adapted the same fix as used for JavaFX Robot
>
> *Bug: *JDK-8162783 <https://bugs.openjdk.java.net/browse/JDK-8162783>.
>
> *Patch: *http://hg.openjdk.java.net/openjfx/9-dev/rt/rev/89a5de54b7dc
>
> New Public API ” BufferedImage createScreenCapture(Rectangle
> screenRect, boolean isHiDPI)”is added,
>
> Which will have a parameter to specify if HiDPI.
>
> It is better to a add public method which returns MultiResolution
> image on HiDPI display and consists of two resoltion variants
> - base image which has size requested by a user
> - high-resolution image which creates an original screen capture
>
> The proposed by your algorithm can be applied to the base image.
> For more details see JDK-8020618 [macosx] java.awt.Robot makes
> blurry screen captures on Retina
>
> Thanks,
> Alexandr.
>
>
>
>
>
> Regards,
> Prem
>
>
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