QGIS composer export to grayscale - qgis

Is there a possibility to create output (export) pdf (or svg) in grayscale using Print Composer in QGIS without changing color schemes in main map window?

In print composer you can preview in greyscale View > Preview > Simulated Photocopy.
Then, in Gimp (or image editor of you preference), you can usually match the simulated results by desaturating the image. In Gimp: Colors > Desaturate. If this doesn't give you the desired result, you can try other greyscaling methods.
You can get Gimp here.

Related

Matlab Spy function too dense

I need to save the visualization of a sparse matrix. I believe the right function to call is Spy(), but when I try to save the image via "saveas(gcf,'Spy.png')" it's just completely blue.
When I open the preview in Matlab its fine . I would just take a screenshot of the preview but I don't want the grey background.

Copy figure in Matlab

I am asking for a solution to the blurred image I get when I use copy figure option in Matlab. For example, when I plot 3d figure in matlab I get the following image (It is the result of printscreen!)..
However, when I use the option copy figure I get a blurred image as the following image
.
How can I avoid this as I need to get high resolution image using copy figure option. Thank you in advance for any help you may lend.
By default, the figure is copied as an Enhanced Metafile (a color graphics format) which works for basic plots such as bar plots, line plots, and other 2D plots but may yield undesirable results for more complex plots as in your case. This is because the rendering of the Metafile content is controlled my Microsoft Word and it may render things differently than MATLAB.
If you need a high resolution image, I would recommend using the print command where you can specify the desired resolution (using the -r option). Then you can import the resulting image into Word
print(gcf, 'myfile.png', '-dpng', '-r300')
Alternately, you can use export_fig from the File Exchange which better preserves the appearance
Another option would be to change the format used by Copy Figure to tell it to use a bitmap instead
Or you can call Copy Figure programmatically and specify a different format (either a bitmap or PDF)
print(gcf, '-clipboard', '-dpdf')

How to improve the quality (smoothness) of lines in contourplots Matlab's

How the line smoothness in a contour plot can be improved for publications? For instance, the dotted lines look really bad, the continuous lines look as if their thickness varies. See below
Here's part of the code:
Vals = [0:5:200]; contourf(X,Y,W,Vals,'EdgeColor','k','LineWidth',1.2,'LineStyle',':');axis square;grid;hold on
Vals = [10:10:200]; contour(X,Y,W,Vals,'EdgeColor','k','LineWidth',1.2);
Vals = [20 : 20 : 200]; [C,h] = contour(X,Y,W,Vals,'Color','k','LineWidth',1.8);
clabel(C,h,'FontName','Palatino Linotype','FontAngle','italic','Fontsize',9,'Color','w')
print -djpeg -r300 filename
Thanks!
Saved as png doesn't help much... check the lines :/ See below:
Check the dotted lines now...
Here's saving as eps (-r1200)... it looks better
Exporting as vector graphics will definitely improve the image over what you see on your screen; I use LaTeX for publications and you can either export to eps for postscript output, and use epstopdf for PDF output, and embed these directly in your document; that would be the best solution.
Additionally, there are also a bunch of general utilities for making your plots look better for camera-ready publications, the most notable that comes to mind is exportfig, which has a load of features to help even with pixel graphics. These go above and beyond just generating smoother-looking images.
http://www.mathworks.us/matlabcentral/fileexchange/23629-exportfig
(copied from that page):
This function saves a figure or single axes to one or more vector and/or bitmap file formats, and/or outputs a rasterized version to the workspace, with the following properties:
Figure/axes reproduced as it appears on screen
Cropped borders (optional)
Embedded fonts (pdf only)
Improved line and grid line styles
Anti-aliased graphics (bitmap formats)
Render images at native resolution (optional for bitmap formats)
Transparent background supported (pdf, eps, png)
Semi-transparent patch objects supported (png only)
RGB, CMYK or grayscale output (CMYK only with pdf, eps, tiff)
Variable image compression, including lossless (pdf, eps, jpg)
Optionally append to file (pdf, tiff)
Vector formats: pdf, eps
Bitmap formats: png, tiff, jpg, bmp, export to workspace
This function is especially suited to exporting figures for use in publications and presentations, because of the high quality and portability of media produced.
Update: I see your example code now. Did you try changing -r300 to some really high value? More pixels per inch should make everything look smoother. For publication, crank it up really high, like -r1200.
Original:
One thing you can try is exporting the plot in some format that supports vector graphics. Matlab supports both PDF and EMF, so try one of those. Export using the saveas command or from the figure's "File -> Save as" menu item. After that, open or import the image file in some other application and hopefully it will look better.
Please add a new screenshot if you get a nicer image!

MATLAB: print pdf in black/white

Matlab prints figures in either black/white or color. A black/white print of a figure is NOT the same as a color print tweaked to black/white: every color including the light ones is translated as black. (Light colors that look good on screen or a color printer look horrible on a black/white printer)
I would like to print a PDF file of a figure. My problem is that there doesn't seem to be a PDF driver for MATLAB that outputs black/white rather than color.
See the print command: -dpdf is the PDF driver but it is color.
Is there any way I can do this?
(edit: http://www.mathworks.com/access/helpdesk/help/techdoc/creating_plots/f3-84337.html#f3-99776 shows the interactive way of doing this, but I need a programmatic method, otherwise it will get tedious rather quickly.)
You can fully automate the print process: http://UndocumentedMatlab.com/blog/customizing-print-setup/
You could convert it to an EPS (-deps or -deps2) and then use eps2pdf (which uses GhostScript) to convert that into a PDF. I generally convert all my figures to this way.

How to change background color of an eps file while converting it to jpeg or png

I am converting eps (Encapsulated PostScript) files to jpeg files with ghostscript. A sample command I use is:
gswin32.exe -sDEVICE=jpeg -dJPEGQ=100 -dNOPAUSE -dBATCH -dSAFER -r600x600 -dGraphicsAlphaBits=4 -dUseCIEColor -dEPSCrop -sOutputFile=”a.jpeg” b.eps
The input eps files come with white backgrounds (I only have their clipping path). What I need to do is change this white background to another color in the output images, or it would be even better if I could make them transparent (output file format would be png). How can I do this?
never tried it myself but you should be able to convert your eps file into png by setting:
-sDEVICE=pngalpha
also the pngalpha device has a -dBackgroundColor option:
-dBackgroundColor=16#RRGGBB (RGB color, default white = 16#ffffff) For
the pngalpha device only, set the
suggested background color in the PNG
bKGD chunk. When a program reading a
PNG file does not support alpha
transparency, the PNG library converts
the image using either a background
color if supplied by the program or
the bKGD chunk. One common web browser
has this problem, so when using on a web page you
would need to use
-dBackgroundColor=16#CCCC00 when creating alpha transparent PNG images
for use on the page.
more details here: Details of Ghostscript output devices see section 3.1. PNG file format
After you've obtained your (white background) images from Ghostscript, you could use ImageMagick's convert or GraphicMagick's gm convert commands to change the white to transparent background:
convert -background transparent my.png my_transp.png