I'm creating a tool to convert pdf's into svg. These pdf's contain graphical data, including large bitmaps at 300 dpi and a bunch of vectors as well. Poking around here on stackoverflow, I've found pdf2svg, which great -- works like a charm, and the vector data is perfect. But it looks like the bitmaps are getting downscaled to 72dpi. The dimensions are still 8x10 in inches, but you can tell that the dpi isn't right when you zoom in. Soft of makes sense that the default values would presume 72 dpi, but I need the full resolution bitmap images.
pdf2svg uses poppler and cairo to make the conversion. I've poked around in the code, and I see where it's creating a poppler page and a cairo surface, and I've seen in the documentation that a poppler page has a concept of "scale" that seems relevant, but I can't figure out where to plug it in. I tried (experimentally) hardcoding the height and width passed into cairo_svg_surface_create to the correct values, but it made the dimensions applied to the whole svg larger, without affecting the embedded bitmap.
poppler_page_get_size (page, &width, &height);
// Open the SVG file
surface = cairo_svg_surface_create(svgFilename, width, height);
drawcontext = cairo_create(surface);
// Render the PDF file into the SVG file
poppler_page_render(page, drawcontext);
cairo_show_page(drawcontext);
I don't think what I'm trying to do is very esoteric, so I'm hoping someone who has experience with the libraries will see my error right away. Any help, of course, would be immensely appreciated.
I just made the change to the source as described in http://lists.freedesktop.org/archives/poppler/2011-December/008451.html and it worked perfectly - the images seem to be at their native resolution.
Replace
poppler_page_render(page, drawcontext);
with
poppler_page_render_for_printing(page, drawcontext);
Does cairo_surface_set_fallback_resolution() perhaps help? (No, I'm not even sure about this myself)
Related
there are a ton of scaling instructions for GIMP but all of them tell you to scale and save easy peasy. I feel like I'm taking crazy pills.
This is what my save or export generates:
How can I simply export a selection? Shouldn't the GIMP instructions include this detail? Sorry for ranting.
In Gimp (and some other popular image editors) the image you work on is actually made of separate images (a.ka.a layers) held together on a "canvas". The "canvas" gives the size of the final image.
There are three different ways to scale things and you have to use the right one:
The Scale tool : scales the active layer by dragging corners. Doesn't change the size of the canvas. This is probably what you used.
Layer>Scale layer: scales the active layer by providing explicit dimensions. Doesn't change the size of the canvas.
Image>Scale image: scales the whole image contents and the canvas. This is probably what you should have used.
What happened to give you the image above is that you resized the layer using the Scale tool, so you got a tiny image in the corner of the canvas, which didn't change size. The uncovered part of the canvas was displayed as a checkerboard pattern. If you exported to a format that supports transparency such as PNG or GIF the image would have been transparent, but since you exported to JPG which doesn't support transparent images Gimp replaced the transparent part by the default background color.
Everything is well explained on their website. https://www.gimp.org/tutorials/GIMP_Quickies/
I am using xlib.
I have an XImage structure filled with information from an XGetImage() call. Is there a popular method to get from XImage to something more meaningful.. namely PNG?
I have looked at libpng, but have heard from pretty much everyone that it's a beast to tame. Would this still be the recommended path to take?
See also How to save XImage as bitmap? though that person had the constraint that they couldn't use a library.
If you can use a library, Cairo is a good one that will do this for you I believe. It has PNG saving dealing with the libpng mess for you, and it has code to get the pixels from X. However, it may make it hard to get pixels from an XImage; it will want to get them from a window or pixmap. If you can just replace your XGetImage() with cairo, then it might work fine. The way you would do things roughly in cairo I think is:
create an Xlib surface pointed at your drawable
save to PNG http://cairographics.org/manual/cairo-PNG-Support.html
You could also use the Xlib surface as source to draw to an image surface, and then do other stuff with the image surface (scale or paint on it or whatever) if you wanted, before saving as PNG.
If you're using any kind of UI toolkit, it probably has code for this too, e.g. GTK+ has gdk_pixbuf_get_from_drawable() etc.
I'm working on SEM image processing application, written in WPF. I have an image display control, derived from Canvas, which displays image & overlays using DrawingVisuals (one for each "layer"). It also implements Zoom & Pan using scale & translate transform, applied on DrawingVisuals.
When I zoom in the image to see individual pixels, they are displayed smooth, evidently using bilinear filtering to stretch the bitmap (no surprise, as WPF is rendered through Direct3D). However, for my use case, I would rather see individual pixels as sharp boxes, as usual in any image editor like Photoshop. That's why user of my app zooms the image -> to be able to operate on pixel level.
Is there such option in WPF (other than manually stretching the bitmap before displaying it)? I was not able to find anything.
thanks in advance,
Zbynek Vrastil
Czech Republic
Finally found an answer, with some help from Experts Exchange. Class RenderOptions defines attached property BitmapScalingMode, which can be set to NearestNeighbor. So,
RenderOptions.SetBitmapScalingMode(imageDisplay, BitmapScalingMode.NearestNeighbor);
does the trick.
Zbynek Vrastil
Hate to put a dampener on things, but if NearestNeighbor works like GDI+, then this will give you a limited success. As you increase magnification in areas of high contrast you might not get the desired results. In GDI+ you find blacks becoming blue, and whites becoming red - again I stress in areas of high contrast! If this isn't the case in WPF, think yourself lucky!
Perhaps a WCF developer could confirm that?
I've found that there are more options to consider, but I can only speak for the GDI+ Graphics class, which might be useful to someone.
Graphics graph = e.Graphics;
graph.InterpolationMode = InterpolationMode.NearestNeighbor;
graph.CompositingQuality = CompositingQuality.AssumeLinear;
graph.SmoothingMode = SmoothingMode.None;
This works for me. I think the SmoothingMode is the trick. Hope this helps someone else out there.
I'm developing a WinForms c# 3.0 application. Our designer created quite a lot of .ico files containing all the needed art. The choice of .ico was made because quite often, the same image is needed in several places in different dimensions.
Now, it seems .ico files are really annoying to use in visual studio. The only way to use those images seems to be through images list (which aren't supported by all controls).
Compared to other resources, you can't write this :
foo.Image = global::RFQHUB.RFQHUBClient.Properties.Resources.foo; // Cannot implicitly convert type 'System.Drawing.Icon' to 'System.Drawing.Image'
Here are the options I'm considering :
create ImageLists of all possible sizes referencing all my icons in my main window. Link these ImageLists from other windows and find a way to export Image objects from the ImageList when I can't use it directly ; since ImageList contains a Draw() method, this should probably be possible.
convert all the x.ico I've got in several x16.gif ...x48.gif, and use those through resources.
I'd be interested to know if some people have been successfully using .ico resources in a Winform application. In so, how did you set up things ?
ICO isn't quite an obsolete format, but it's close. It's still useful for your application icon, but for almost everything else, it's better to use an ImageList for each size that you need. And it's much faster to populate an ImageList from a bitmap that contains multiple images layed out in a grid.
You also want to use an Alpha channel transparency in your bitmaps to get the best result, so storing them as .PNG files in your resources is the best way to go, since PNG supports an alpha channel. ICO and GIF files support only single bit for transparency - every pixel is either fully opaque or fully transparent. An 8 bit alpha channel for transparency looks much nicer.
If you can send your artist back to the drawing board then you should do so, and have him/her do full anti-aliased images with alpha. If you can't, then I suggest that you write a small program to convert all of your icon files into bitmaps suitable for loading into ImageLists.
Convert the images into PNG. Point. Whoever decided to use .ico files to start with should get talked to in private - the argument holds no ground.
If i have a logo, let's say done as a jpg or even a png. Any suggestion for how I can use that to define a path geometry? It would be really good if any suggestions could be provided for how i can do it in blend.
Thanks
Yes - I just tackled this problem for an LOB application two days ago.
I can't offer advice for Blend (though I've read that it can be done in Expression Designer). However, the best free tool I've found for this is called InkScape (http://www.inkscape.org).
It's opensource, and while it's intended primarily for editing SVG vector-based images, it has two key features that are useful to us WPFers:
It can vectorize (i.e. "trace") raster images like bitmaps and jpegs, albeit not as well as one would hope, and
It can export the vector image as XAML
You'll invariably find that you get better results from loading vector formats (like SVG, EMF, WMF, etc) and saving to XAML, than if you try to convert a bitmap/jpeg... simply because the process of vectorizing a raster image is error prone at best. So if you want to bring a company logo into XAML, try to get hold of the source files used to create the logo (perhaps done in Illustrator?) and import that into InkScape.
If this post is helpful, please be kind and give it a one-up.
Jasema is a terrific tool right for the job.
Also, don't be shy to use Blend - it is somewhat more difficult to use (drawing shapes using pen) but it gets easier pretty fast. Switch on gridlines and optionally snap to them for good results.
What both Jasema and Blend are lacking, is the ability to easily create shapes with a central symmetry (like stars), so I took parts from Jasema and created my own tool (named Radius) that works a bit like a combination of a ruler and compass.
I have a good idea but you're png, bmp, jpg or other non vector file is must be very simple because we need best scan results and only use inkscape.
Step: Drag and drop your file workspace on Inkscape, download free.
Tip: If your image is color white, Top menu item File->Document Properties-> heck Checkerboard Background and if you want uncheck Page border show.
Step: Top menu item Path-> Trace Bitmap-> Mode check what you want property, i usually use color property and if your file is png check Remove Background then click OK, then wait again Ok button is Enable and close window.
Step: Now you have a two layer, top layer vektor file and bottom layer your file. Select vector file and top menu item Edit-> XML Editor-> select svg path and look side column, d name propery in your data path value.
But this method may not always work or may not give the desired results and draw your own shapes with the scape so you can get the path data from the XML editor.
Example, my first tests this like:
and after working on it some more:
I've solved my problem (export an image as XAML) using Microsoft Expression Design 4 (Free Version). I've downloaded from the link
http://www.microsoft.com/en-us/download/confirmation.aspx?id=36180
As input, I had Adobe Ilustrator files.
Adobe Illustrator / CorelDraw is perhaps the best tool out there for these operations that I have used.
Personally, I prefer illustrator for on-screen media. These tracings can be exported into several formats such as EPS, SVG, AI, or even XAML (with this plugin)
Best of Luck !!!!
I have recently been struggling with this myself. I had a set of icons done in data and needed to update them to look nicer.
I tried everything, manually typing them out. drawing in svg, converting svg to xaml.
in the end i found a list of open source icons from google material icons.
I then used this to convert from the svg files to data
https://github.com/BerndK/SvgToXaml
It works well but not for the icons i drew myself.
I decided to place all the icons data i convert into an app i built myself that will give you the data and a preview of the icon. feel free to use and contribute. I will keep updating as much as i can.
https://github.com/sgreaves1/XamlIcons
Convert your image from png to svg in online converter, then drop file into this site http://inloop.github.io/svg2android/ and you will see pathData of your image like below shown in my image.