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2020-05-20 16:36:15 -0600 | edited question | why is imshow window 2:1 scaled on one pc, 1:1 scaled on another with idential code? why is imshow window 2:1 scaled on one pc, 1:1 scaled on another with idential code? I recently updated/rebuilt OpenCV 4 |
2020-05-20 16:32:02 -0600 | asked a question | why is imshow window 2:1 scaled on one pc, 1:1 scaled on another with idential code? why is imshow window 2:1 scaled on one pc, 1:1 scaled on another with idential code? I recently updated/rebuilt OpenCV 4 |
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2019-11-26 10:30:14 -0600 | edited question | why is type Mat still not resolved in my new eclipse install? why is type Mat still not resolved in my new eclipse install? I've installed versions of OpenCV a few times in Windows 7 |
2019-11-26 10:29:55 -0600 | edited question | why is type Mat still not resolved in my new eclipse install? why is type Mat still not resolved in my new eclipse install? I've installed versions of OpenCV a few times in Windows 7 |
2019-11-26 10:22:30 -0600 | commented question | why is type Mat still not resolved in my new eclipse install? Hi berak, usually I wouldn't do screenshots but in this case it's the context around the code that I'm trying to show, i |
2019-11-25 18:03:01 -0600 | edited question | why is type Mat still not resolved in my new eclipse install? why is type Mat still not resolved in my new eclipse install? I've installed versions of OpenCV a few times in Windows 7 |
2019-11-25 18:02:03 -0600 | edited question | why is type Mat still not resolved in my new eclipse install? why is type Mat still not resolved in my new eclipse install? I've installed versions of OpenCV a few times in Windows 7 |
2019-11-25 17:59:19 -0600 | edited question | why is type Mat still not resolved in my new eclipse install? why is type Mat still not resolved in my new eclipse install? I've installed versions of OpenCV a few times in Windows 7 |
2019-11-25 17:59:11 -0600 | edited question | why is type Mat still not resolved in my new eclipse install? why is type Mat still not resolved in my new eclipse install? I've installed versions of OpenCV a few times in Windows 7 |
2019-11-25 17:56:20 -0600 | asked a question | why is type Mat still not resolved in my new eclipse install? why is type Mat still not resolved in my new eclipse install? I've installed versions of OpenCV a few times in Windows 7 |
2019-05-31 16:04:40 -0600 | asked a question | why do I get "random" window size with resizeWindow()? why do I get "random" window size with resizeWindow()? I'm using Ubuntu 18.04 with Eclipse C++/CUDA toolchain. I built |
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2019-05-16 15:03:40 -0600 | edited question | How do I fix “undefined reference to `cv::cuda::…” linker errors in Eclipse? How do I fix “undefined reference to `cv::cuda::…” linker errors in Eclipse? Disclaimer: I'm new to this whole Linux and |
2019-05-16 15:02:38 -0600 | asked a question | How do I fix “undefined reference to `cv::cuda::…” linker errors in Eclipse? How do I fix “undefined reference to `cv::cuda::…” linker errors in Eclipse? Disclaimer: I'm new to this whole Linux and |
2017-02-14 18:39:25 -0600 | commented answer | how to return array of minimum values between two arrays ok. Just a note that (min) also works. And I see that the include file <windows.h>, which I am using in order to get my display size, is where min(a,b) and max(a,b) are defined as macros, so this is why I am having this problem. I found this link: [http://stackoverflow.com/questions/1632145/use-of-min-and-max-functions-in-c (http://stackoverflow.com/questions/16...)] |
2017-02-13 23:43:21 -0600 | commented answer | how to return array of minimum values between two arrays The (cv::min) solution worked. The #define may have also worked but elsewhere in my code I was using the standard C overloads for max() and min(), so those lines were now getting flagged. Perhaps this is a bug in OpenCV, that it doesn't recognize array operators max() or min() unless specified as was done here? Or maybe it's because I'm using VSE? Many thanks! |
2017-02-13 20:31:43 -0600 | commented answer | how to return array of minimum values between two arrays yea, I tried both of those ways but it still doesn't like the min part. When I hover over the "min" word I get the message |
2017-02-13 17:09:19 -0600 | asked a question | how to return array of minimum values between two arrays According to the help docs, there is a function min() that says it computes an output array that is the per element minimum of two input arrays or array and scalar, but when I use this in my code it's not recognized as valid OpenCV (no overload given). What is the function to do this minimum? I'm using 3.2.0 in Win7 on VSE2015 C/C++. Thanks. |
2017-02-03 23:17:21 -0600 | commented question | why are mat operators seeing wrong type? Got it. I was finally able to get this to work by doing as you said, combined with simplifying my Mat declarations. Might have avoided this whole confusion if OpenCV used some other symbol for matrix multiply ("#" would make sense to me!) Anyhow, you both lead me to the solution so thanks for the numerous replies. |
2017-02-03 19:35:02 -0600 | commented question | why are mat operators seeing wrong type? By adding the following line right above the crash line I was able to see that invgain_map was being set to array type 0 despite being declared as type 5: But now riddle me this: when I add this line just above the cerr line to convert invgain_map back to type 5: it still crashes on the following multiply line even though the cerr output now shows 5 5, so I know types are the same. So what gives? Plus I am now getting this error: How can the lengths be different? |
2017-02-03 16:21:23 -0600 | commented answer | why is createButton not implemented? I guess as a non-developer I don't understand why the trackbars and buttons require different libraries. Seems reasonable that if you use one you'd usually want the other, and while trackbars could be used as binary selectors they take up WAY too much window area (By the way why is this? I see so much wasted space below the bottom trackbar that 2-3 more could easily fit there.) What's so special about buttons anyway that they need their own library? So are trackbars the only gui option for default builds of OpenCV? |
2017-02-03 12:37:32 -0600 | commented question | why are mat operators seeing wrong type? Even if map array is CV_16S because the blur function output it that way, why wouldn't the gain_map = map / 255.0 assignment keep gain_map as CV_32F? I don't use map again in the code, only gain_map. So what I hear you saying is that, unlike just about every other language I've seen, in OpenCV a Matrix can actually CHANGE it's own type on the fly even when it's declared to be a specific type? If true then that's crazy! I tried adding this line: map.convertTo(map, CV_32F); prior to dividing by 255.0 and assigning to gain_map, but it doesn't help. |
2017-02-03 12:23:09 -0600 | commented question | why are mat operators seeing wrong type? I left out the blur intentionally because it's not relevant to the problem. but here's the line where regions and map are declared simply as Mat types earlier, so they get converted to whatever is necessary by their compare and blur functions, respectively. so gain_map = map / 255.0 and should still be CV_32F type at this point, no? my first attempts at this code actually wasn't trying to set output/result Mat's to something, so here I am now trying to make it happy by forcing everything to be CV_32F. but it's not happy. |
2017-02-03 12:00:30 -0600 | commented question | why are mat operators seeing wrong type? will do next time. by the way I'm using 3.2.0 on windows 7 |
2017-02-03 11:34:55 -0600 | asked a question | why are mat operators seeing wrong type? I'm at a loss here, why does my code crash with the error: Below is basically what I'm trying to do, some lines may be unnecessary but I've been removing all assumptions about auto-allocation and matrix depths. Note, live_image comes into my function as "const Mat" with depth CV_16U. As noted it crashes on the last multiply line. When I replace * with multiply() I get a different but related error: But how in the world can my types be different? I left nothing to chance. Thanks for any help. |
2017-02-03 10:38:04 -0600 | commented answer | why is createButton not implemented? thanks for reply. ok, but what's the harm with the developers compiling OpenCV with the QT libs? else disabled features like createbutton should have a disclaimer in the docs so novice people don't waste time crashing. |
2017-01-28 18:47:50 -0600 | asked a question | why is createButton not implemented? I am using precompiled release 3.2.0 within VSE 2015 and would like to add a button to my window, since I am getting good use out of the trackbars. But when I run my exe it crashes and I get this message written to the console: OpenCV Error: The function/feature is not implemented (The library is compiled without QT support) in cv::createButton, file C:\build\master_winpack-build-win64-vc14\opencv\modules\highgui\src\window.cpp, line 526 Does this mean there is no way for a button to work? Is there a plan to offer a version of OpenCV with the button features working? If not, why? I'm not a hard core programmer so I don't know the process of compiling my own OpenCV installation and I don't have time to deal with that anyhow. Thanks. |
2017-01-23 22:24:45 -0600 | commented answer | how to make a composite mask? That makes it simple, thanks for pointing it out. I couldn't find any description of this in the documentation. |
2017-01-23 19:10:11 -0600 | commented answer | how to make a composite mask? Anyhow, it would seem trivial for OpenCV to add two mask-level functions that treat mask elements pixelwise. Nice and clean. i.e. for each array pixel, mask_or() would be zero, zero = 0 zero, nonzero = 255 nonzero, nonzero = 255 mask_and() would be zero, zero = 0 zero, nonzero = 0 nonzero, nonzero = 255 |
2017-01-23 18:59:13 -0600 | commented answer | how to make a composite mask? what is maskX? |
2017-01-23 16:53:31 -0600 | commented answer | how to make a composite mask? I can't guarantee that the values are all the same, just that they are zero or nonzero. One mask might have 0 and 255 values but another may have 0 and 8bit grayscale values and another may have 0 and 1 values. Am I correct in saying that if you were to bitwise_and a mask of all 128s with a mask of all 1s you would get a mask of all 0s, but pixelwise should return a mask of all 255 which is what I want since both masks contain all nonzero (i.e. true) pixels. Sounds like there is no convenient command for this desired action. |
2017-01-23 16:09:34 -0600 | asked a question | how to make a composite mask? I have several masks that I created using the compare() function. They are all CV_8U type. Now I want to make a composite mask in one step, if possible, using all of these submasks. I know how to make a logical OR'd mask using final_mask = mask1 + mask2 + mask3... but I want a logical AND'd mask. Doing this: final_mask = mask1 * mask2 * mask3... hangs up my application, likely because the result blows up too large for the saturate_cast<> operation. How do I do this? I see there's a bitwise_and() but I want pixelwise. Thanks. |
2017-01-16 17:02:17 -0600 | commented answer | how is b=a.clone() different than a.copyTo(b)? which is faster? Thanks for this code to run. It gives me practically identical results for clone and copyTo. So am I correct to understand that clone is actually just a copyTo operation nested within a function call? Why would this be necessary? Anyhow, I have my answer in that I will just use copyTo. |
2017-01-16 00:36:01 -0600 | asked a question | how is b=a.clone() different than a.copyTo(b)? which is faster? For an image processing demo I need to squeeze every bit of optimization out of my code to get a higher frame rate, but I'm familiar with hardware programming (VHDL) and not so much with CPU programming languages. So it's not clear to me how much faster code can run by moving statements such as variable declarations outside of loops and functions, i.e., does encountering a type declaration millions of times actually slow down execution? To this end, there also seem to be different methods to performing the same OpenCV array tasks on Mat types. My big question at this time is whether I should use clone or copyTo if I simply want to make a copy of an existing Mat array. Does it matter if the dst array has already been declared with the same size as the src? Thanks. |
2016-12-25 00:05:20 -0600 | asked a question | what is difference between versions 2.4.13 and 3.2? I am a complete newbie to opencv and I want to install it to use in visual studio express 2015. looks like two different versions are being maintained on the web site but no explanation, which should I install for win7pro 64-bit? I don't want to compile my own libraries, simpler is better. thanks. |