The issue
I'm chasing a color issue that occurs during a gm convert of a jpg in CMYK colorspace to png. Just when I thought I'd isolated the issue and wanted to upload the images I realized that my issue has none to do with GraphicsMagick as the upload preview already showed the issue on the source image.
The source image
The majority of image tools (including XnView, browser) renders it light green.
Some image tools (including Faststone Image Viewer) render this image with dark green color:
To persist the issue
Running gm convert isolated-in.jpg png:isolated-out.png persists this light green for all image renderes.
The desired outcome
The dark green color is the desired outcome. I understand that there must be a corruption of the color profile of the input image. Infact, there seems to be none. However, some image tools render it correctly, making me beliefe there is a differet "guess" on the profile. What are those image tools doing so that it appears dark green? And, can I, with gm identify and/or gm convert correct for the missing/corrupted color profile of the source and persist the correct color, which is dark green?
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.
Here is an SVG image I want to convert to PNG with librsvg in my program.
This is a PNG version of the SVG exported from Inkscape:
This is a bitmap of the same SVG exported with librsvg:
Only the white portions of the image are exported. The black portions, despite being well-defined in the background, appear transparent.
This problem occurs whether I use the librsvg API or the program rsvg-convert. You can use the W3 validator to see that the SVG's markup is valid.
I notice the same thing happens in the thumbnails of the SVGs in my file browser. Perhaps they're using librsvg?
Upon digging into the files I discovered that, for some reason, the fill of the black portion was set to "fill:currentColor". I don't know where that came from, but changing it to "fill:#000000" fixed the problem.
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.
I have some .bmp files that have some color (maybe black) that is supposed to show as transparent when the graphic is displayed on top a form, so the form color comes through the transparent areas. But by default, when I put these images in an Image View, the black/transparent areas show up as BLACK!
I'm thinking I need to either:
- alter how the NSImageView shows the image, so that a certain color is transparent, or
- modify the .bmp files somehow to make that color suitable for transparency in an NSImageView
But I don't know enough about graphics files, transparency(alpha), NSImageView, nor the image editing tools. I'm trying to use Gimp, but...not sure what I'm doing yet. It seems like there is already a color that should be transparent in the current .bmp file.
I'm sure its something simple for setting NSImageView, or editing my file, or perhaps making a mask for the image, but I don't know how yet. I've looked at various filters in IB for NSImageView, but have not found where to set the transparent color, nor how to grab that color from the image file to make sure I use the correct value.
Thanks in advance for any assistance. (I tried to post some images, but because I'm new, I could not.)
Beau
I'm not a Cocoa developer, but in Gimp try adding an alpha channel to your image (a layer mask, perhaps) then saving as a 32-bit PNG image (with an alpha channel), then load that PNG directly into your NSImageView. If you want to make the black pixels transparent in Gimp use the magic-wand tool to select them (use magic-wand with 0 tolerance) and just delete the contents of the selection then save as a PNG directly.
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.