I need to add GPS metadata to TIFF / DNG images using LibTIFF. I know very little about LibTIFF. To be extra annoying, I have to hack this into an existing LuaJIT module with minimal footprint (Edit: to be clear, I don't need an answer in LuaJIT!).
From this question, it seems like I need to set the TIFFTAG_SUBIFD field first, then write the main IFD, then write the GPS IFD. I'm confused on two points:
There's a special LibTIFF name for TIFFTAG_GPSIFD, and I'm not sure where that comes in, or if that's supposed to happen in place of setting TIFFTAG_SUBIFD.
I don't know how to assemble the GPS IFD in the first place. If indeed I'm supposed to set TIFFTAG_SUBIFD and use TIFFWriteDirectory() to close the main IFD, I assume that any following calls to TIFFSetField() will write to the GPS IFD, but there are no LibTIFF names for the fields inside the GPS IFD. That makes me think I'm missing something.
I imagine it's clear that I don't really know what I'm doing with LibTIFF, so any help is appreciated. Feel free to ignore the fact that I'm in LuaJIT and just tell me what this might look like in C.
For reference, this question seems to accomplish the same task in Java, but I don't understand it well enough to translate.
Finally, here's a general idea of what I have now, but this is obviously incomplete. the "v_int" style functions are just helpers to return the appropriate C variable from ffi.new().
local fdt = tiff.TIFFOpen(ofname, 'w')
-- Set all the fields in the main IFD here
-- ...
if self.scfg.gps then
-- Prepare libtiff for a subIFD
-- https://stackoverflow.com/questions/11959617/in-a-tiff-create-a-sub-ifd-with-thumbnail-libtiff#11998400
subifd_n = v_int(1)
subifd_offsets = ffi.new(string.format('toff_t[%i]', subifd_n), {v_uint32(0)})
tiff.TIFFSetField(fdt, C.TIFFTAG_SUBIFD, v_int(subifd_n), subifd_offsets)
end
local bytes_per_pixel = self.sample_depth / 8
tiff.TIFFWriteRawStrip(fdt, 0, data_raw, self.frame_height * self.frame_width * bytes_per_pixel)
if self.scfg.gps then
tiff.TIFFWriteDirectory(fdt) -- Finish main IFD
b2 = v_unit8(2)
b0 = v_uint8(0)
tiff.TIFFSetField(fdt, 0, b2, b2, b0, b0) -- GPSVersionID
end
tiff.TIFFClose(fdt) -- Closes currently-open IFD (?)
Any help is very much appreciated!
I'm having a problem where Octave will render figures just fine in the figure box, but then refuses to properly export to PNG when I use the print() command. This is also true when I try other formats like EPS or JPG.
My current version of Octave is 3.8.1-1ubuntu1, which is up to date at the time of this post. My Ubuntu version is also 14.04. I do not receive any error messages when the code runs.
The script commands used to plot are pretty basic. For example:
linewidth = 4;
xStr = 'Particle Diameter (\mum)';
yStr = 'Scattering Cross-Section (\mum^2)';
FontName = 'Times New Roman';
LabelFontSize = 22;
AxisFontSize = 18;
F1 = figure(1);
clf('reset');
plot(diameter*1e6,sigma_0*1e12,'k','linewidth',linewidth);
hold on
plot(diameter*1e6,sigma_1*1e12,'r','linewidth',linewidth);
X = xlabel(xStr);
set(X,'FontName',FontName,'fontsize',LabelFontSize);
Y = ylabel(yStr);
set(Y,'FontName',FontName,'fontsize',LabelFontSize);
axis([xMin xMax sigMin sigMax]);
set(gca,'fontsize',AxisFontSize,'linewidth',2);
legend('2.0 \mum','3.8 \mum',4);
print(F1,'Mie.png','-dpng');
The strange thing is that I have other images from months ago that rendered the LaTex bits just fine, and even used nearly identical code. That almost seems like some recent software upgrade may have killed my plotting.
I appreciate any help you can give me. This issue is driving me nuts.
This is a known problem when using the OpenGL toolkits (graphics_toolkit FLTK) which is default in octave3.8.x. Previous versions used gnuplot for printing.
So you have two choices:
Switch back to gnuplot with "graphics_toolkit gnuplot" before doing any plotting. You may also add this to your .octaverc so it's set every time you start octave
Use LaTex output: http://wiki.octave.org/Printing_with_FLTK
I am using Maya to do some procedural work, and I have a lot of textures that I need to load into Maya, and they all have transparencies (alpha channels). I would very much like to be able to automate this process. Using PyMEL, I can create my textures and hook them up to a shader, but the alpha doesn't set properly by default. There is an attribute in the psdFileTex node called "Alpha to Use", and it must be set to "Transparency" in order for my alpha channel to work. My question is this - how do I use PyMEL scripting to set the "Alpha to Use" attribute properly?
Here is the code I am using to set up my textures:
import pymel.core as pm
pm.shadingNode('lambert', asShader=True, name='myShader1')
pm.sets(renderable=True, noSurfaceShader=True, empty=True, name='myShader1SG')
pm.connectAttr('myShader1.outColor', 'myShader1SG.surfaceShader', f=True)
pm.shadingNode('psdFileTex', asTexture=True, name='myShader1PSD')
pm.connectAttr('myShader1PSD.outColor', 'myShader1.color')
pm.connectAttr('myShader1PSD.outTransparency', 'myShader1.transparency')
pm.setAttr('myShader1ColorPSD.fileTextureName', '<pathway>/myShader1_texture.psd', type='string')
If anyone can help me, I would really appreciate it.
Thanks
With any node, you can use listAttr() to get the available editable attributes. Run listAttr('myShaderPSD'), note in it's output, there will be two attributes called 'alpha' and 'alphaList'. Alpha, will return you the current selected alpha channel. AlphaList will return you however many alpha channels you have in your psd.
Example
pm.PyNode('myShader1PSD').alphaList.get()
# Result: [u'Alpha 1', u'Alpha 2'] #
If you know you'll only ever be using just the one alpha, or the first alpha channel, you can simply do this.
psdShader = pm.PyNode('myShader1PSD')
alphaList = psdShader.alphaList.get()
if (len(alphaList) > 0):
psdShader.alpha.set(alphaList[0])
else:
// No alpha channel
pass
Remember that lists start iterating from 0, so our first alpha channel will be located at position 0.
Additionally and unrelated, while you're still using derivative commands of the maya.core converted for Pymel, there's still some commands you can use to help make your code read nicer.
pm.setAttr('myShader1ColorPSD.fileTextureName', '<pathway>/myShader1_texture.psd', type='string')
We can convert this to pymel like so:
pm.PyNode('myShader1ColorPSD').fileTextureName.set('<pathway>/myShader1_texture.psd')
And:
pm.connectAttr('myShader1PSD.outColor', 'myShader1.color')
Can be converted to:
pm.connect('myShader1PSD.outColor', 'myShader1.color')
While they may only be small changes, it reads just the little bit nicer, and it's native PyMel.
Anyway, I hope I have helped you!
In my C/C++ program, I'm using OpenCV to capture images from my webcam. The camera (Logitech QuickCam IM) can capture at resolutions 320x240, 640x480 and 1280x960. But, for some strange reason, OpenCV gives me images of resolution 320x240 only. Calls to change the resolution using cvSetCaptureProperty() with other resolution values just don't work. How do I capture images with the other resolutions possible with my webcam?
I'm using openCV 1.1pre1 under Windows (videoinput library is used by default by this version of openCv under windows).
With these instructions I can set camera resolution. Note that I call the old cvCreateCameraCapture instead of cvCaptureFromCam.
capture = cvCreateCameraCapture(cameraIndex);
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_WIDTH, 640 );
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_HEIGHT, 480 );
videoFrame = cvQueryFrame(capture);
I've tested it with Logitech, Trust and Philips webcams
There doesn't seem to be a solution. The resolution can be increased to 640x480 using this hack shared by lifebelt77. Here are the details reproduced:
Add to highgui.h:
#define CV_CAP_PROP_DIALOG_DISPLAY 8
#define CV_CAP_PROP_DIALOG_FORMAT 9
#define CV_CAP_PROP_DIALOG_SOURCE 10
#define CV_CAP_PROP_DIALOG_COMPRESSION 11
#define CV_CAP_PROP_FRAME_WIDTH_HEIGHT 12
Add the function icvSetPropertyCAM_VFW to cvcap.cpp:
static int icvSetPropertyCAM_VFW( CvCaptureCAM_VFW* capture, int property_id, double value )
{
int result = -1;
CAPSTATUS capstat;
CAPTUREPARMS capparam;
BITMAPINFO btmp;
switch( property_id )
{
case CV_CAP_PROP_DIALOG_DISPLAY:
result = capDlgVideoDisplay(capture->capWnd);
//SendMessage(capture->capWnd,WM_CAP_DLG_VIDEODISPLAY,0,0);
break;
case CV_CAP_PROP_DIALOG_FORMAT:
result = capDlgVideoFormat(capture->capWnd);
//SendMessage(capture->capWnd,WM_CAP_DLG_VIDEOFORMAT,0,0);
break;
case CV_CAP_PROP_DIALOG_SOURCE:
result = capDlgVideoSource(capture->capWnd);
//SendMessage(capture->capWnd,WM_CAP_DLG_VIDEOSOURCE,0,0);
break;
case CV_CAP_PROP_DIALOG_COMPRESSION:
result = capDlgVideoCompression(capture->capWnd);
break;
case CV_CAP_PROP_FRAME_WIDTH_HEIGHT:
capGetVideoFormat(capture->capWnd, &btmp, sizeof(BITMAPINFO));
btmp.bmiHeader.biWidth = floor(value/1000);
btmp.bmiHeader.biHeight = value-floor(value/1000)*1000;
btmp.bmiHeader.biSizeImage = btmp.bmiHeader.biHeight *
btmp.bmiHeader.biWidth * btmp.bmiHeader.biPlanes *
btmp.bmiHeader.biBitCount / 8;
capSetVideoFormat(capture->capWnd, &btmp, sizeof(BITMAPINFO));
break;
default:
break;
}
return result;
}
and edit captureCAM_VFW_vtable as following:
static CvCaptureVTable captureCAM_VFW_vtable =
{
6,
(CvCaptureCloseFunc)icvCloseCAM_VFW,
(CvCaptureGrabFrameFunc)icvGrabFrameCAM_VFW,
(CvCaptureRetrieveFrameFunc)icvRetrieveFrameCAM_VFW,
(CvCaptureGetPropertyFunc)icvGetPropertyCAM_VFW,
(CvCaptureSetPropertyFunc)icvSetPropertyCAM_VFW, // was NULL
(CvCaptureGetDescriptionFunc)0
};
Now rebuilt highgui.dll.
I've done image processing in linux before and skipped OpenCV's built in camera functionality because it's (as you've discovered) incomplete.
Depending on your OS you may have more luck going straight to the hardware through normal channels as opposed to through openCV. If you are using Linux, video4linux or video4linux2 should give you relatively trivial access to USB webcams and you can use libavc1394 for firewire. Depending on the device and the quality of the example code you follow, you should be able to get the device running with the parameters you want in an hour or two.
Edited to add: You are on your own if its Windows. I imagine it's not much more difficult but I've never done it.
I strongly suggest using VideoInput lib, it supports any DirectShow device (even multiple devices at the same time) and is more configurable. You'll spend five minutes make it play with OpenCV.
Check this ticket out:
https://code.ros.org/trac/opencv/ticket/376
"The solution is to use the newer libv4l-based wrapper.
install libv4l-dev (this is how it's called in Ubuntu)
rerun cmake, you will see "V4L/V4L2: Using libv4l"
rerun make. now the resolution can be changed. tested with built-in isight on MBP."
This fixed it for me using Ubuntu and might aswell work for you.
Code I finally got working in Python once Aaron Haun pointed out I needed to define the arguments of the set function before using them.
#Camera_Get_Set.py
#By Forrest L. Erickson of VRX Company Inc. 8-31-12.
#Opens the camera and reads and reports the settings.
#Then tries to set for higher resolution.
#Workes with Logitech C525 for resolutions 960 by 720 and 1600 by 896
import cv2.cv as cv
import numpy
CV_CAP_PROP_POS_MSEC = 0
CV_CAP_PROP_POS_FRAMES = 1
CV_CAP_PROP_POS_AVI_RATIO = 2
CV_CAP_PROP_FRAME_WIDTH = 3
CV_CAP_PROP_FRAME_HEIGHT = 4
CV_CAP_PROP_FPS = 5
CV_CAP_PROP_POS_FOURCC = 6
CV_CAP_PROP_POS_FRAME_COUNT = 7
CV_CAP_PROP_BRIGHTNESS = 8
CV_CAP_PROP_CONTRAST = 9
CV_CAP_PROP_SATURATION = 10
CV_CAP_PROP_HUE = 11
CV_CAPTURE_PROPERTIES = tuple({
CV_CAP_PROP_POS_MSEC,
CV_CAP_PROP_POS_FRAMES,
CV_CAP_PROP_POS_AVI_RATIO,
CV_CAP_PROP_FRAME_WIDTH,
CV_CAP_PROP_FRAME_HEIGHT,
CV_CAP_PROP_FPS,
CV_CAP_PROP_POS_FOURCC,
CV_CAP_PROP_POS_FRAME_COUNT,
CV_CAP_PROP_BRIGHTNESS,
CV_CAP_PROP_CONTRAST,
CV_CAP_PROP_SATURATION,
CV_CAP_PROP_HUE})
CV_CAPTURE_PROPERTIES_NAMES = [
"CV_CAP_PROP_POS_MSEC",
"CV_CAP_PROP_POS_FRAMES",
"CV_CAP_PROP_POS_AVI_RATIO",
"CV_CAP_PROP_FRAME_WIDTH",
"CV_CAP_PROP_FRAME_HEIGHT",
"CV_CAP_PROP_FPS",
"CV_CAP_PROP_POS_FOURCC",
"CV_CAP_PROP_POS_FRAME_COUNT",
"CV_CAP_PROP_BRIGHTNESS",
"CV_CAP_PROP_CONTRAST",
"CV_CAP_PROP_SATURATION",
"CV_CAP_PROP_HUE"]
capture = cv.CaptureFromCAM(0)
print ("\nCamera properties before query of frame.")
for i in range(len(CV_CAPTURE_PROPERTIES_NAMES)):
# camera_valeus =[CV_CAPTURE_PROPERTIES_NAMES, foo]
foo = cv.GetCaptureProperty(capture, CV_CAPTURE_PROPERTIES[i])
camera_values =[CV_CAPTURE_PROPERTIES_NAMES[i], foo]
# print str(camera_values)
print str(CV_CAPTURE_PROPERTIES_NAMES[i]) + ": " + str(foo)
print ("\nOpen a window for display of image")
cv.NamedWindow("Camera", 1)
while True:
img = cv.QueryFrame(capture)
cv.ShowImage("Camera", img)
if cv.WaitKey(10) == 27:
break
cv.DestroyWindow("Camera")
#cv.SetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH, 1024)
#cv.SetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT, 768)
cv.SetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH, 1600)
cv.SetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT, 896)
print ("\nCamera properties after query and display of frame.")
for i in range(len(CV_CAPTURE_PROPERTIES_NAMES)):
# camera_valeus =[CV_CAPTURE_PROPERTIES_NAMES, foo]
foo = cv.GetCaptureProperty(capture, CV_CAPTURE_PROPERTIES[i])
camera_values =[CV_CAPTURE_PROPERTIES_NAMES[i], foo]
# print str(camera_values)
print str(CV_CAPTURE_PROPERTIES_NAMES[i]) + ": " + str(foo)
print ("/nOpen a window for display of image")
cv.NamedWindow("Camera", 1)
while True:
img = cv.QueryFrame(capture)
cv.ShowImage("Camera", img)
if cv.WaitKey(10) == 27:
break
cv.DestroyWindow("Camera")
I am using debian and ubuntu, i had the same problem, i couldn't change the resolution of video input using CV_CAP_PROP_FRAME_WIDTH and CV_CAP_PROP_FRAME_HEIGHT
I turned out that the reason was a missing library.
I installed lib4l-dev through synaptic, rebuilt OpenCV and the problem is SOLVED!
I am posting this to ensure that no one else wastes time on this setproperty function. I spent 2 days on this to see that nothing seems to be working. So I dug out the code (I had installed the library the first time around). This is what actually happens - cvSetCaptureProperty, calls setProperty inside CvCapture class and lo behold setProperty does nothing. It just returns false.
Instead I'll pick up using another library to feed OpenCV a capture video/images. I am using OpenCV 2.2
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_WIDTH, WIDTH );
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_HEIGHT, HEIGHT);
cvQueryFrame(capture);
That will not work with OpenCV 2.2, but if you use OpenCV 2.1 it will work fine !
If you are on windows platform, try DirectShow (IAMStreamConfig).
http://msdn.microsoft.com/en-us/library/dd319784%28v=vs.85%29.aspx
Under Windows try to use VideoInput library:
http://robocraft.ru/blog/computervision/420.html
I find that in Windows (from Win98 to WinXP SP3), OpenCV will often use Microsoft's VFW library for camera access. The problem with this is that it is often very slow (say a max of 15 FPS frame capture) and buggy (hence why cvSetCaptureProperty often doesn't work). Luckily, you can usually change the resolution in other software (particularly "AMCAP", which is a demo program that is easily available) and it will effect the resolution that OpenCV will use. For example, you can run AMCAP to set the resolution to 640x480, and then OpenCV will use that by default from that point onwards!
But if you can use a different Windows camera access library such as the "videoInput" library http://muonics.net/school/spring05/videoInput/ that accesses the camera using very efficient DirectShow (part of DirectX). Or if you have a professional quality camera, then often it will come with a custom API that lets you access the camera, and you could use that for fast access with the ability to change resolution and many other things.
Just one information that could be valuable for people having difficulties to change the default capture resolution (640 x 480) ! I experimented myself a such problem with opencv 2.4.x and one Logitech camera ... and found one workaround !
The behaviour I detected is that the default format is setup as initial parameters when camera capture is started (cvCreateCameraCapture), and all request to change height or width :
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_WIDTH, ...
or
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_HEIGHT, ...
are not possible afterwards ! Effectively, I discovered with adding return error of ioctl functions that V4l2 driver is returning EBUSY for thet requests !
Therefore, one workaround should be to change the default value directly in highgui/cap_v4l.cpp :
*#define DEFAULT_V4L_WIDTH 1280 // Originally 640*
*#define DEFAULT_V4L_HEIGHT 720 // Originally 480*
After that, I just recompiled opencv ... and arrived to get 1280 x 720 without any problem ! Of course, a better fix should be to stop the acquisition, change the parameters, and restart stream after, but I'm not enough familiar with opencv for doing that !
Hope it will help.
Michel BEGEY
Try this:
capture = cvCreateCameraCapture(-1);
//set resolution
cvSetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH, frameWidth);
cvSetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT, frameHeight);
cvQueryFrame(capture);
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_WIDTH, any_supported_size );
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_HEIGHT, any_supported_size);
cvQueryFrame(capture);
should be just enough!