I am working on an app that saves canvas content as a raster image, then user saves it to his computer to print with a printer or print office. If you visit the link, you can click button Export and click the link to save the file. I know I can't handle CMYK with canvas and the file is sent as RGB. But I can control color values that are used for generating the image. For example, if I know that some object is any shade of black, I can put it on a separate layer and then join black layer and colored layer together on server side. May be it can help with the issue. So, I wonder if any of you faced a similar challenge to generate color-accurate image ready for print with canvas. Or may be using SVG can help me by any chance? Please share your hints.
Note: I use Python as a server-side language but I think any language library/solution will work for me if it does the job.
CMYK is always dependant on the kind of paper. E.g. the total ink for very dark color tones might be around 350% on glossy paper, but only 200% on coated paper. So you have to know the target medium in advance. There is no 1:1 conversion from RGB to CMYK.
Nowadays most printers handle RGB just fine, I wonder why you really need to do the separation at all.
If you insist on converting to CMYK, have a look at http://cue.yellowmagic.info/softwares/separate-plus/index.html for a possibility to do that with a GIMP plugin. I am quite sure that it is scriptable server-side.
Related
i am developing the code for a simple game in AS3 and i have all the graphic assets made by a designer.
He wants all the textual messages (i.e. win, lose, lives, etc.) to be done exactly as in the original photoshop drawing, they have lots of visual fx on them.
Since these messages inside the game are dynamic, I tried to use normal textfields and replicate the visual fx with Flash filters, but the result is not even comparable.
I think i could try to export from photoshop a spritesheet with the all the image characters, or the single image characters one by one, and replace my old textfields with sprites/movieclips in which i would load the specific image characters based on the string i need to show to the enduser, but i don't know precisely how to do it.
Does anyone have some hints on how to achieve this result? Better to use a separate class and image library? I googled online hoping to find some class or method alike to customize a little for my needs, but unfortunately i haven't found anything!
You could add all the graphics to the library exporting them with each name.
Than call them when needed creating a MC. If useful, you could store the names in an array and use it to simplify your script (it depends on usage)
Ok, after some more research, i found out my main problem in not finding answers to my problem was the terms of research i was using.
I was erroneously looking for "AS3 string replace with images" or "text replace with images in Flash", while the correct question was: "how to use a BITMAP FONT in AS3".
I was sure someone else had to do what i'm trying to do (like in old games where texts were all image sprites) but i didn't know how to find it!
So, this is the solution i found, i still have to refine the workflow but it's a good starting point:
Create a custom Bitmamp font using the SHOEBOX tool in conjunction with photoshop, where you will be able to apply all the raster fx you want (here's the tutorial: http://renderhjs.net/shoebox/bitmapFont.htm)
You will obtain a .fnt file (descriptor) and a .png image (font characters atlas)
You will need to flip the png image vertically: apparently, a lot of bitmap text engines work with flipped characters, and i found this one to be working like this as well
Once you have these files, use the BMFontRenderer AS3 class to embed your bitmap font into an AS3 project of your choice (tutorial here: http://blog.bengarney.com/2011/12/07/fast-bitmap-fonts-in-flash/)
I hope it will be useful for others who may need to replace standard text in Flash with font images.
Is there a possibility to make image colors exactly the same as HTML colors?
I have a rounded corners box, the corners are images and the background color is HTML, on my laptop it looks flawless, but on good monitors a difference in colors is noticeable.
Is it true that it isn't possible to have HTML generated colors exactly match image colors?
edit: I am using Photoshop and am using the exact hex equivalent of the RGB colors.
Another potential solution: you're seeing a color shift caused by color profiles.
These could be due to how those other monitors are configured (you can update your machine to use a specific profile; folks like designers will do this to make sure colors are accurate in photography or print design) or due to how your images are saved when exporting them from your favorite image editing tool (I'm looking at you, Photoshop). These issues can and will occur regardless of whether or not your hex colors are spot on and are ridiculously frustrating.
Give that link a shot; if you're dealing with an embedded color profile issue, that might get you going in the right direction.
Edit: That you're exporting from Photoshop makes me think this is the likely culprit.
If you use the same colors, e.g. #E1E1E1 in your CSS and your image (a tool like 'GIMP' will assist you with a color picker where you can directly enter these hex values) the colors will be identical.
My guess is your problem is most likely compression (by saving as .jpg and the artifacts it introduces). Use other formats (like the lossless PNG format) or save your JPG in a lossless way (with the quality slider up to 100 in most tools).
Browsers / monitors can look a tiny bit different for some colors. Matching up certain colors may prove to be a difficult task even if you are matching an image with the same hex value as the one you are using in your css. (this will work for most cases but not always) My recommendation is to use web safe colors where possible, these colors tend to render the same on multiple displays.
I was wondering how one would go about automatically making an image map based on just the opaque parts of a png image. You are normally able to click anywhere on the png image, even transparent areas, and it will register as clicking the image. Is there any way to exclude transparent areas and only have opaque areas register?
I assume there is some sort of javascript color detection feature, or something along those lines. I have access to jQuery on my website, as well.
Thank you for taking time to read and answer.
Trying to do this with images will be a major headache. It's possible that there is a javascript library out there to detect colors, but that's very complex stuff.
Maybe give svg a go if the graphics are simple.
This site (not mine) has a nice map using svg.
I'm coding a website with:
background-color:#070707;
That color should be a very dark gray, just the way I see it in photoshop.
Now when I launch this in my browser (the background-color is set on the body using CSS, so it's not an exported image), the color is darker than in Photoshop.
I know there can be differences when exporting images due to color profiling, but when setting the color code, how can this be different from photoshop?
Photoshop might be rendering the colors using its built-in color matching/proofing engine while the browser probably does not use one.
Try getting Photoshop's color settings right (CTRL+SHIFT+K) and change proof setup (View > Proof Setup) to match that of a typical monitor.
I think it depends which color model are you using in photoshop:
RGB
CMYK
LAB
Here is a good tutorial about the exact usage and differences of each of them:
http://www.deke.com/content/photoshop-top-40-feature-6-rgb-cmyk-and-lab
Could you be defining it in photoshop as something other than a hex number? IIRC, there's Hue/Sat/something that can also give a 6-digit output. You're not viewing it on different monitors or something?
#070707 is not dark gray. It is almost black. Are you sure that the color palette in photoshop does not include alpha. Else try 'Choose Copy Color As HTML' option in color palette.
Saving a file for the web is best done with "save for web" or ctrl/shift/alt (on the pc). This gives you many options for color output - ones that shouldn't change. However, if you choose a color out of the web gambut, it may be "correcting" it for the web. I agree with Glasnt's response - Check it under different monitors.
Gifs always make guesses to color combinations. Jpgs are given a range of accuracy. Pings are the most correct to color exports out of the series. Make sure you are saving RGB instead of any other format (LAB, CMYK, etc.).
Are you using mac or pc?
bam
I've been thinking of a dynamic way of creating a CAPTCHA that uses morphing shapes or dynamic colors.
My first idea is to have a graphic, flash or something, that gradually changes from, say a square into a sphere. The user will be required to click the button when it becomes spherical enough.
Second idea is to have an area of color that slowly changes from, say, red to blue and the user will be required to press a button when it becomes blue enough.
Third idea is a combination of both methods.
I'd say the difficulty will be to match the clicks with the transitions. But it should be hard for automated code to detect shades or shapes.
Can people please offer some comments on my idea.
edit -
Thanks for the feedback. I'm now considering using a flash based video playback of a server fed video feed of a few colored shapes that morph into other colored shapes. The user will be required to pause the feed when the colors and shapes match some canned questions: such as : click on the video when you see two green squares turn into 3 blue triangles. The shapes will be amongst over overlapping and moving morphing shapes. Fun for the whole family!
Color is a bad idea as (a) its very easy for a computer to detect; (b) very hard for some humans — the color blind — to detect. Even if you're OK with denying access to the disabled, you'd have to worry about different monitors, systems, lighting conditions, etc. giving rise to different color perceptions.
How hard do you think it is for a computer to compare the red component and blue component in a pixel (or averaged over several pixels)? Trivial. So this isn't a problem for a computer.
Similarly, it isn't that hard to program the difference between a square and a circle. One has strait lines, one doesn't!
Good idea, you could also do it so that the shapes keep turning or moving.
I don't know if it would be safer than a regular letter capcha tho.
I'm not sure why you think color would be any harder to detect than text. Shapes possibly, but they would have to be more complex than n-sided polygons. The gradual animation is a good idea however. But if you can code it to show, someone can code something that watches it.
The real test is to prove humanness by identifying semantic meanings, rather than syntactic meanings.
For instance show pictures of animals and make the user click when a bird shows up. Or just say "click on the thing that can fly." And show some pictures of animals. This would be rather unbeatable by a machine until all images had been cataloged. The trouble with CAPTCHA of course is trying to make semantics with syntax. Therefore defeating itself from the onset.
You're on the right track, and I'm sure your proof of concepts are interesting. But remember: made by a computer: solved by a computer.
Although these ideas will almost certainly work, it's a security-through-obscurity effect. Classic CAPTCHA images are "one-way" in that the correct answer can't (theoretically) be deduced by a computer. The problem with saying "click here when the image turns blue" is that a computer could easily do this, if somebody considered the stakes to be worth developing a program for.
Additionally, unusual captchas will force your users to think. Depending on your audience this may mean losing some users.
I did a fair bit of research when developing a CAPTCHA system, and the classic method of printing text to an image seems to be the most effective. The trick is not in having lots of "background noise" behind the text, or different colours. It's about the following two things:
1) Random text kerning, with most or all letters slightly overlapping each other.
2) Random distortion, translation and rotation of the text.
If you have a look at Google's CAPTCHA, they pretty well only have those two features: https://www.google.com/accounts/NewAccount?service=mail