I'm looking for a simpler way (if there is one) of finding out what RGB is used by the brush that Windows uses to erase a window background.
The problem I'm trying to solve in the most elegant way is as follows:
When registering the class, I specify a brush this way:
hbrBackground := GetSysColorBrush(COLOR_WINDOW);
when processing the WM_PAINT, I'm using ExtTextOut specifying ETO_OPAQUE and the rectangle (so it clears it.)
Currently, I am using:
SetBkColor(dc, GetSysColor(COLOR_WINDOW));
That has an obvious downside, if the brush used when registering the class changes then, the programmer has to remember or be aware that the same change must be made in the SetBkColor instruction found in WM_PAINT. That's not good.
One way of solving the problem is to use GetClassLongPtr to get the background brush then, use GetObject on the brush to get its LOGBRUSH which contains the brush's RGB which can be passed to SetBkColor.
My question is: is using GetClassLongPtr followed by GetObject the simplest way of getting the RGB value I need to pass to SetBkColor ? I'm hoping there is a simpler (more straightforward) way than that.
Thank you very much for your help.
PS: I'm looking for a straight API solution in C/C++ or Delphi. No .net or any other framework solution.
This may sound like stupid question, but for me it's important.
I don't have much experience with using Photoshop, because Inkscape is perfect for my needs (web). Now I would need to create something and print it. I know that color mode for printing should be CMYK.
Because I am more familiar with Inkscape(that does not support CMYK), can I create PDF in that program and then import it into Photoshop and change color mode to CMYK. Is that valid? It shows that color mode is changed, but is that all? Because this is not for me and I just want to know if person that I wouk this for will not have any problems when it comes to printing. How can I make sure that conversion to CMYK was good?
One more question. In Inkscape I can not crop image, but I can mask or clip it. Basically, image still exist, but you see only portion of it. When it comes to printing will printer print full image or just that portion of it or I will need to crop image?
For most part, when you print an RGB file on your printer, the printer will convert it to CMYK. It's ability to do so "well" will depend on how accurate you need it to be & what color profile it is printing from (sRGB generally turns out better than say AdobeRGB).
The main reason for you to convert a file is so that you can make any fine tune adjustments to the image after the change. So you're not leaving it to the printer to decide and possibly mess up.
I'm not familiar with InkScape so don't know how it'll export said artwork. When you open it in Photoshop however, you will be able to see if it tacked it on there. Then you can crop if need be.
Hope that helps.
I'm having an issue with attempting to save some plots with transparent ellipsoids on them if I attempt to save them with .ps/.eps extensions.
Here's the plot saved as a .png:
If I choose to save it as a .ps/.eps here is what it looks like:
How I got around this, was to use ImageMagick to convert the original png to a ps. The only problem is that the image in png format is about 90k, and it becomes just under 4M after conversion. This is not good since I have a lot of these images, and it will take too much time to compile my latex document. Does anyone have a solution to this?
The problem is that eps does not support transparencies natively.
There are few options:
rasterize the image and embed in a eps file (like #Molly suggests) or exporting to pdf and converting with some external tool (like gs) (which usually relies as well on rasterization)
'mimic' transparency, giving a colour that looks like the transparent one on a given background.
I discussed this for sure once on the matplotlib mailing list, and I got the suggestion to rasterize, which is not feasible as you get either pixellized or huge figures. And they don't scale very nicely when put into, e.g., a publication.
I personally use the second approach, and although not ideal, I found it good enough. I wrote a small python script that implements the algorithm from this SO post to obtain a solid RGB representation of a colour with a give transparency
EDIT
In the specific case of your plot try to use the zorder keyword to order the parts plotted. Try to use zorder=10 for the blue ellipse, zorder=11 for the green and zorder=12 for the hexbins.
This way the blue should be below everything, then the green ellipse and finally the hexbins. And the plot should be readable also with solid colors. And if you like the shades of blue and green that you have in png, you can try to play with mimic_alpha.py.
EDIT 2
If you are 100% sure that you have to use eps, there are a couple of workarounds that come to my mind (and that are definitely uglier than your plot):
Just draw the ellipse borders on top of the hexbins.
Get centre and amplitude of each hexagon, (possibly discard all zero bins) and make a scatter plot using the same colour map as in hexbin and adjusting the marker size and shape as you like. You might want to redraw the ellipses borders on top of that
Another alternative would be to save them to pdf
savefig('myfigure.pdf')
That works with pdflatex, if that was the reason why you needed to use eps and not svg.
You can rasterize the figure before saving it to preserve transparency in the eps file:
ax.set_rasterized(True)
plt.savefig('rasterized_fig.eps')
I had the same problem. To avoid rasterizing, you can save the image as a pdf and then run (on unixish systems at least) in a terminal:
pdftops -eps my.pdf my.eps
Which gives a .eps file as output.
I solved this by:
1) adding a set_rasterization_zorder(1) when defining the figure area:
fxsize=16
fysize=8
f = figure(num=None, figsize=(fxsize, fysize), dpi=180, facecolor='w',
edgecolor='k')
plt.subplots_adjust(
left = (18/25.4)/fxsize,
bottom = (13/25.4)/fysize,
right = 1 - (8/25.4)/fxsize,
top = 1 - (8/25.4)/fysize)
subplots_adjust(hspace=0,wspace=0.1)
#f.suptitle('An overall title', size=20)
gs0 = gridspec.GridSpec(1, 2)
gs11 = gridspec.GridSpecFromSubplotSpec(1, 1, subplot_spec=gs0[0])
ax110 = plt.Subplot(f, gs11[0,0])
f.add_subplot(ax110)
ax110.set_rasterization_zorder(1)
2) a zorder=0 in each alpha=anynumber in the plot:
ax110.scatter(xs1,ys1 , marker='o', color='gray' , s=1.5,zorder=0,alpha=0.3)#, label=label_bg)
and
3) finally a rasterized=True when saving:
P.savefig(str(PLOTFILENAME)+'.eps', rasterized=True)
Note that this may not work as expected with the transparent keyword to savefig because an RGBA colour with alpha<1 on transparent background will be rendered the same as the RGB colour with alpha=1.
As mentioned above, the best and easiest choice (if you do not want to loose resolution) is to rasterized the figure
f = plt.figure()
f.set_rasterized(True)
ax = f.add_subplot(111)
ax.set_rasterized(True)
f.savefig('figure_name.eps',rasterized=True,dpi=300)
This way, you can manage the size by dpi option as well. In fact, you can also play with the zorder below you want to apply the rasterization:
ax.set_rasterization_zorder(0)
Note: It is important to keep f.set_rasterized(True) when you use plt.subplot and plt.subplot2grid functions. Otherwise, label and tick area will not appear in the .eps file
My solution is to export the plot as .eps, load it up to Inkscape for example, then Ungroup the plot, select the object that I want to set the transparency and just edit the Opacity of the Fill in the "Fill and Stroke" tab.
You can save the file as .svg if you want to tweak it later, or export the image for a publication.
If you are writing the academic paper in latex, I would recommend you export the .pdf file rather than .eps. The .pdf format supports transparency perfectly and has good compression efficiency, and most importantly, can be easily edited in Adobe Illustrator.
If you wanna further edit the graph (NOT EDITING DATA! I MEAN, FOR GOOD-LOOKING), you could open the exported graph, in Adobe Acrobat - Edit - Copy elements into Adobe Illustrator. The two software can handle everything perfectly.
I work happily with this method. Everything clear, editable and small-size. Hope can help.
How do I make a picture transparent in VB6.0 so that when I add image and put the picture, the background will show behind it?
From Rod Stephen's excellent VB Helper site (particularly good on graphics in VB6):
HowTo: Overlay one image on another with a transparent color by using PSet
Description from the site:
This program simply loops through the pixels in the images. For each
image in top-to-bottom order, the program looks for a color other than
the one defined as transparent. When it finds such a color, it stops
looking at the images and sets the output pixel's color using PSet.
Note that there are faster ways to access color values in V 6 and VB
.NET, and that there are faster methods for merging images if you have
an overlay mask. Note also that VB .NET provides tools for setting a
transparent color for an image so this problem is trivial in VB .NET.
i think you should use an ocx and dll library to fix it
You can use 3rd party .ocx files to get that effect.checkout this link http://www.vbforums.com/showthread.php?636390-vb6-Transparent-PictureBox
I am looking at way of finding the color space of a CGContext?
CGBitmapContextGetColorSpace() will not work as I am working with general context and not bitmap context.
Thank you,
Rahul
There does not seem to be any way to retrieve this information; for a system-provided CGContext, the color space actually used may not even be any of the publicly-defined color spaces.
There also does not seem to be any way to retrieve the current fill or stroke color or color space. But there also does not seem to be any documented restriction on the types of colors that may be passed to CGContextSetFillColorWithColor or CGContextSetStrokeColorWithColor, so in general you should just set the color you want and let the framework handle translating that into the appropriate format for the CGContext.
You can't directly read colorspace data from CGContext properties. So you'll have to work around this shortcoming in the CGContext API by
- intercepting property updates on the way to the CGContext of interest, or
- outputting PDF data whose stream you then examine for the colorspace & color data.
colorspaceref CGContextGetStrokeColorSpace(ccontextref);
colorspaceref CGContextGetFillColorSpace(ccontextref);
but this are priate.