Remove background colour of a PNG file in CSS - css

How to remove the background color of a png using CSS?
I am working on a website where I need to stack a png icon over a background image. Since the image is from an external API, I cannot edit it, beforehand.

Blend Modes
So whilst browser support for these is pretty low, if you don't need to worry about IE/Edge/Mobile browsers this should be fine.
Pretty simple to use, what you'd want to do is apply your background-image and a background-color followed by your specified background-blend-mode
Whilst none will give you a perfect background change like that in image editing software, you'll get pretty close with multiply.
Eg:
background-image: url('yourimage.png');
background-color: blue;
background-blend-mode: multiply;

Option 1: Pure CSS [Limited Support]
The only way to do this is to use mix-blend-mode or background-blend-mode but unfortunately it is not supported in IE and Edge (check the support level here) If you need IE support see option 2.
You can read more about this CSS property here. By putting the blend mode to screen you can remove the white background of your png image.
background-image: url(face.jpg);
background-color: red;
background-blend-mode: multiply;
Option 2: ImageMagick [Need Backend]
You can create your own backend endpoint that fetches the image from the API, remove the background using ImageMagick and return the new transparent image. If the Icon is small you can even embed the image into the API as encode base64. Base65 encoding and decoding has full browser support.

Related

How to make css background-size scale linearly?

So when I scale a background image in CSS3, using the background-size property, like this:
.one {
background-image: url(sprites/1.png);
background-size: 100% 100%;
}
then it scales the picture:
How can I make it so the picture is not blurred like that? Is it possible without a higher resolution image?
If the whole background image is purely just a black line, as shown, before you save the image, change it to an indexed image (instead of RGB), and give it an index of only two colours. That way there will be no blur (antialiasing) and it will scale perfectly well. It will also make your background image a very tiny file size, which helps for quick loading. Save the indexed image either as png, or gif.
Alternatively you could use a image type like SVG which handles scale operations.
https://en.wikipedia.org/wiki/Scalable_Vector_Graphics
Though the SVG Specification primarily focuses on vector graphics markup language, its design includes the basic capabilities of a page description language like Adobe's PDF. It contains provisions for rich graphics, and is compatible with CSS for styling purposes. SVG has the information needed to place each glyph and image in a chosen location on a printed page

CSS: Browser shows a different color code than the one set on CSS stylesheet

I have a div with the property:
background-color: #327EB2;
When I open the page on a browser I notice that a different color is shown. If I capture the screen and open the captured image on Photoshop, I can see that the color code captured is actually #437BB6. I have nothing set with that color in my CSS stylesheet.
I've tested on different monitors, different color resolutions, different browsers and versions from FF 4+ to IE8+, Opera, Chrome, Safari, etc...
Actually I don't think that's a problem of the monitor, resolution or browser version, because the problem is that the code of the shown color is actually a totally different one!
Also, Photoshop warns me about #327EB2 which is not a "Web Safe color", but I don't think this is the problem because I often use non-websafe colors in my sheets and I've never had an issue like that.
** Fiddle: http://jsfiddle.net/286tE/
*UPDATE
The problem is that the div has a background image and a background-color. The background color has to match the last pixel's color of the background image (as usual), which is #327EB2.
Anyway, I can see a different color from the last pixel of the image to the background-color:
http://test.testblueday.eu/test/cbsissue.png
You can see the page here, the problem is shown after the "Top Marchi" list on the left side:
http://test.testblueday.eu/test/cbstest.html
I've left the plain CSS and JS (not compressed) to let you see all the properties.
** UPDATE 2
I use Mac, but we can see the problem also on Windows.
You problem has nothing to do with the CSS, the problem is in the image!
This is because the examples supplied by you show the correct #327EB2 at the extra background (the one "coloured" via CSS), and that is enough to know that the CSS part is ok.
Beware of colour corrections/management done in the file exported via Photoshop.
If you can't colour manage/revert to the desired colour, another solution is doing the opposite, change the CSS colour to match the last row of the image.
As far as I can see, everything works correctly. Your image at the bottom has color with code '#1080b3' - I just downloaded that picture (gradient_box_emboss.jpg) and took a color with colorpicker in GIMP. When I modify css like this:
.embosser {
background: #1080B3 url('/images/gradient_box_emboss.jpg') right top no-repeat;
color: white;
padding: 5px 6px;
}
Difference is missing. When I printscreen your site and paste it into GIMP, color picker shows color of that "wrong" background is #327eb2. When I open your image you have in your question, color of background is #307db7. It is in jpg and I suppose some color information were lost while compressing raw data to .jpg. Possibly, something similar happens when you are trying to get color in photoshop.
Possibly problem rise when you convert images from one format to another. Simplest fix is above - change color of background to one you have on your image.

CSS Image Overlay

I am creating a template for my company that will be used down the road on a variety of different clients sites, and they will all range in color. I have created icons for this template that are currently black (or white) and I want to be able to control the color of these icons via css. They are one simple color and in photoshop if you do a blending option of color overlay and choose 1 color, they look great. Is this possible to do in css so when someone is editing this template for future clients that they can control the icon colors in css instead of having to edit every icon in photoshop every time?
It's possible to change the color of a logo in CSS, but not to solve the problem you are talking about. To make a changeable logo you would make a PNG with transparency where the logo is and background color (of the webpage) in the negative space. Then put it over a P or div that has the logo color you want as its background color.
Trouble is, you have just exchanged having a flexible logo color for an inflexible "background" color.
Better to just include both colors of logo, white and black, as part of a "package" that is put up with all websites. Just call the one you want in CSS where you want it.
If your icon is a shape you can make in css, it could work, but I have never heard of anybody doing what you are talking about before.
Its not possible to change the color of icon using css. You can shape it,you can give transparency,opacity etc
Not possible via CSS. You can use some dynamic technologies like Canvas, but it's not good way. I would rather create tool to create icon sets in desired color. You can do it with PHP (phpGD or ImageMagick here is example of similiar problem).
You can do this with images (as long as the background colour is consistent) but it requires thinking outside the box a bit. Open the icon's image file in Photoshop (or similar). Edit it so that the "icon" part (i.e. the bit that is currently black) is transparent, and the background (i.e. the bit that isn't what the icon depicts) is filled white (or whatever the background colour of the site is). Essentially you've "reversed the polarity" of the image. Put the image in the web page, then use CSS to specify it's background-color. Your icon should appear in that colour. Edit: Something like this: http://coding.smashingmagazine.com/2010/10/31/transparent-css-sprites/
A [potentially] much simpler approach would be to use an icon font like http://pictos.cc/. That's just text really, so you can colour it with CSS as usual.
You can do this with CSS pseudo elements and translucent overlays. You can follow the instructions here: http://www.impressivewebs.com/image-tint-blend-css/
If you have a vector logo, you can do this with SVG logos even easier (by altering your SVG colors).
If you make the icon images into a font, then you have full control over both size and color via CSS. Check out the very popular Font-Awesome font, designed to compliment Twitter Bootstrap.
I'm no font expert, but if this approach sounds like a fit, you'll do something like:
create vector graphics from your icons
load them into a font editor, like FontLab Studio
add the new font to your favorite web application. If you need a guide for this, FontSquirrel.com generates great #font-face markup to include their library of free fonts.
It can be done and works well with Firefox and Chrome as far as I know. Example below.
http://demosthenes.info/blog/532/Convert-Images-To-Black-And-White-With-CSS
img {
filter: grayscale(100%);
-webkit-filter: grayscale(100%);
-moz-filter: grayscale(100%);
-ms-filter: grayscale(100%);
-o-filter: grayscale(100%);
}
I would say the best/easiest answer is to use SVG. The logo should probably be in a vector format to start with so that it can be scaled without detail loss from business cards to billboards.
SVG 'images' are based on shapes. Give the shape you want to change a name, and then address it in CSS to change it's colour.
This article:
http://css-tricks.com/using-svg/
and this example:
http://codepen.io/chriscoyier/pen/evcBu
Do an excellent job of explaining how to achieve this and also show off other possibilities.
SVG at least the basics are now widely supported, ie8 is the only browser holding it back and even so there are ways around this via rendering SVG as an image on the fly.

Reflection gradients using CSS in android browser

I have some CSS for displaying a reflection on an element which uses -webkit-gradient to fade out:
.foo { -webkit-box-reflect: below 0 -webkit-gradient(linear, left top, left bottom, from(rgba(255, 255, 255, 0)), to(rgba(255, 255, 255, 0.5)), color-stop(0.7, transparent)); }
On browsers which support -webkit-box-reflect such as chrome, this displays a reflection of the element which gradually fades out as expected.
On browsers which don't support it at all, no reflection is show.
However, on Android's browser, a reflection is shown, but doesn't fade out.
Is there any way of getting Android to either:
fade out the reflection, or
not show the reflection at all.
I know I could use javascript to detect the browser and change the style accordingly, but I'd much prefer a CSS-only solution.
Without an example file or link, it is a little difficult to see what you need.
I also played with some reflection stuff a few months ago and didn't find anything that could do what you describe. I have some steps to get you what you want, outside of code. I recommend the item you wish to reflect be a PNG on a transparent background, to start.
The steps:
1.Take the image into your favorite image manipulation program (ex. Photoshop)
Double or extend the image canvas the necessary amount to include the reflection in the appropriate direction
Duplicate the layer (Photoshop-Layer/Duplicate Layer)
Reflect the image. (Photoshop-Layer/Image Rotation/Flip Canvas (your direction))
Move the duplicated layer such that it appears as a mirror using the Move tool
Select the Marquis tool, and set the edge blur to about 50% of your original image width.
Drag your cursor over the "reflected" layer, don't worry if it says the selection lines won't be visible, unless it says nothing was selected. If it says nothing was selected, reduce your edge blur to about 25% and try again.
Once you have a selection, be it visible or not, delete the selected area. This should give you a "reflected" look.
If desired, add a background on a layer below everything else.
Save your image as a jpg if you don't have a transparent background or a png if you do. Use it in place of the image you were reflecting and fading with code. This will be mostly browser compatible.
CSS isn't designed to handle stuff like that. In other words: no, it's not possible.
I'm having similar problems trying to do things with background gradients in the Android browser, and it appears completely unsupported
Unfortunately the above answer is right, there isn't a way to split your declaration up in a nice progressively enhanced way. You could use JavaScript/modernizr as you mentioned, and at least set a support class(es) so you don't actually have to flip the style within code.
You could try reproducing this effect with a HTML canvas element, using drawImage with your image and transforming it. Although canvas can be slow in mobile webkit.
Good luck
do gradients work at all in the android browser?
if they do, make sure you're using the correct version. There's an old webkit format you may need to use.
If not, just use modernizr to hide it on places that don't support gradients.

Is it possible to have a transparent photoshop image render in CSS?

Is it possible to have a transparent photoshop image render in CSS? I tried saving as jpg and gif with transparency selected but when I overlay it in css it shows the background color behind it and not the image which is under it. I played with the z-index and it didn't help.
Thanks
JPEG images do not support transparency.
You need to save the image as a PNG file, which does support transparency.
If you need to support IE6, you'll also need to use the filter proeprty.
You need to save it using an image format that supports the type of transparency that you want. The JPEG format doesn't support transparency at all.
There are two types of transparency, transparency index and alpha channel. The GIF and PNG-8 formats support transparency index, i.e. one of the 256 colors are chosen to represent transparency. That means that each pixel in the image can only be either 100% transparent or 100% solid.
The PNG-24 format support alpha channel. That is transparency value for each pixel, so that it can be anything from 100% transparent to 100% solid (in 256 levels).
If your image has mostly fully transparent or fully solid pixels, you can use transparency index, but if it has a lot of partly transparent pixels, you have to use alpha channel.
Note that older versions of IE has problems displaying the transparency in PNG-24 images correctly.
First, have a transparent background (as in no background) as the first layer of your photoshop file.
Be sure it has grey and white squares in the background, which means it is transparent.
When you're ready to save, go to the File Menu, and hit Save for Web
Select the PNG file format and be sure it has "Transparency" checked.
Just press SAVE and give it a name and that photoshop image will be saved into a transparent background PNG file which presents more colors, and it's smaller than a GIF file and is as good as a jpg.
As SLaks pointed out, use a PNG image file for this. JPEG won't do, I am not sure why GIF wouldn't work...
I took a look at a project I was doing involving some translucent background and its CSS, and this is what I found:
background-image: url(../images/translucent_white.png);
So it really is that simple. Just save your picture with transparency as a PNG.
You need to save it as a .png file as mentioned but this is tricky when it comes to IE6. It depends on if the image you have is using a gradient that transistition to the transparency. For instance a shadow.
If you have an image that has a shadow (or any gradient) than you are best off using a .png but this will now work for IE6 and you should follow the advice of SLaks. In my experience though I stay away from javascript fixes like this and just choose to save the image w/ the desired background.
If you do no have a gradient then the .gif is the way to go as it will be supported in all browsers.
I recommend using a .gif filetype; it supports transparent backgrounds and works in most cases. .jpgs don't support transparent backgrounds at all. .pngs support nice alpha-transparent backgrounds, but not in IE6. (Using the AlphaImageLoader filter can cause page slowdown and browser crashes.)
First off, make sure that your image has a transparent background in Photoshop - often a white and grey checkerboard. Then, choose "Save for Web" (or something close to that, it varies in different versions) from the File menu, choose whatever GIF preset works best, and be sure that "Transparency" is checked.

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