I am using PNG type image with transparent background in picturebox control with stretch Mode in Windows CE. But in pocket pc device it shows wrong behaviour. I provide its screen shot below:
How can I resolve it?
As you've discovered, ARGB transparency isn't supported in the CF. You need to change your image and then use ColorKey transparency. See the answers to this question for more links.
looks to me like you have used an alpha type png RGBA, which is not displayable by your code and its converted to RGB so just displays your background colour as one rectangle.
Greg.
Related
I try to design some icons for gnome (symbolic icons) but the problem is that gnome files make them completely black(it fills the transparent areas in the icons)
how i can solve this problem
Use SVG or PNG for the image file of the icon.
https://specifications.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html
Some other image formats don't support transparent white space. I recommend testing your icons in an image viewer that supports white space. If you get a similar effect, mind this is not in the editing program so what your seeing in the image decoding library making sense of the image, then you should try to change image format to a different format that supports transparent white space. If you are using Gnome, Eye of Gnome, the default image viewer, should show a gray checkered pattern where there is white space.
This is an issue for xamarin.uwp and FFImageLoading, but it reproduces only in UWP.
The issue with optimized files by Photoshop.
I optimized my images on a server with Photoshop. I exported them with option Smaller File (8-bit) after it I got black color in UWP (ios and android are ok).
When I deleted downsample parameters for CachedImage(FFImageLoading control) then transparency was back.
Example:
And files before optimization and after it
https://github.com/luberda-molinet/FFImageLoading/wiki/Xamarin.Forms-API
Says that the CachedImage class does not support transparency on iOS or Windows Phone. Perhaps since the article was written iOS support has been added but not yet UWP.
It's a bug, please make a separate issue on project site. It's related to this:
8 bit PNG can have no more than 256 colors. A part of the PNG file structure holds pointers to 256 colors and then each pixel in the image gets its color from one of those pointers. Thus each pixel only consumes one bytem its 0-255 value pointing to its color on the palette. On the other hand, a 32 bit PNG is 4 bytes per pixel and each pixel can represent a different ARGB color value.
Pixel Format
// Edit I created it: https://github.com/luberda-molinet/FFImageLoading/issues/986
I was trying to use a coloured texture (PNG 24/RGB) for a POI (bicycle_parking) and it was not being rendered. It was added properly as a texture, it just won't be rendered on the POI.
After some testing I came to believe that POIs only accept grayscale textures that can later be filled up with a color. Is this right?
I also found out that the icon needs to be of a specific size (I got it working only at 32x32 pixels and 512x512, but the scaling did not make it look good). Is there any information regarding this?
Now I have a grayscale icon (mostly white) but the fill color does not change the white as expected. This is as far as I got..
Here's a set of icons similar to the ones I need to render into POIs
How could I achieve adding this type of icons as the texture of a POI? Workarounds/hacks are welcome as well :)
Thanks!
The texture of the Poi must have a size that is a power of 2 and goes from 32x32 up until 512x512. Also make sure that the colour code of that image is RGB anything else wont work. For the best visual result you have to create 3 sets of pngs for different screen densities, for example see heatmap_legend.png then look at heatmap_legend#2x.png and heatmap_legend#3x.png, you can find them in the "common" folder.
So turns out that the color wasn't a problem after all. It was quite tricky to get one image working, but once I had the image working, adding color to it and saving the PNG worked just fine.
The problem with the image size I experienced is still happening. You need to export it in 32x32, 64x64 or 96x96 in order to StyleEditor not to crash when opening the file.
the img I made is suposed to be transparent but when I upload it to my web page it has a dark blueish background, just don't understand why .. please help, how can I check if its fully transparent ?
what browser? transparency in gif is just a color that you set as transparent and the browser must interpret it as transparent. Some older browsers don't work with it. If it displays correctly in any modern browser such as chrome for example, then the transparency is correctly set in your gif.
You can try another different software to save the GIF or a different method of selecting transparency, for example, by mask instead of by color. Or try a PNG format instead.
World Map Images in Adobe Illustrator CS5
I have an image Map in illustrator CS5 which i want to save in GIF so as to reduce its size for web use. But when i save it, the map boundaries are having some white pixels all along the map boundaries of map.
I really dont know why has happened to it, but cant save it in Png-8, png-24 formate due to size constraint.
Any meaningful answer will be highly appreciate and thanks in advance.
Is your background a non-changable color? Maybe you can save the image with the same color as a background.
The problem is gifs don't support true transparency.
If this doesn't work can you provide the image you are trying to save (gif and png, I don't have AI right now)? Maybe there will be something I can do about the size or clearing the gif's edges.
transparent GIFs don't have an 8-bit alpha channel, like PNG does: a pixel in a GIF is either there, or it's not: if it's there, you can't see through it. This often means that an edge between transparent and non-transparent areas looks blocky.
There are two ways to deal with this... either use a PNG 24 (and the Illustrator Save for Web feature will help you to make it smaller), or in Illustrator create a background color layer behind your image before you export to GIF. If this background color layer is the same as the website you put the image on, the edges will blend nicely.