RMagick Image text question

rubyonrails-talk
1

Hi there! I'm studying RMagick graphics manipulation gem, and I need to put small text about size 8 to 11 px on pictures. I found that text() method prints quite blurred text. And I could not get clear text chosing different values for methods font, font_family, font_style, font_weigth.

I attached a picture. In the left of it you can see what RMagick generates for me and in the right you can see the example of clear text I need RMagick to generate for me.

What can I do to get clear text. Any ideas?

Attachments: http://www.ruby-forum.com/attachment/2862/Image_text.png

2

Zhan Tuaev wrote:

Hi there! I'm studying RMagick graphics manipulation gem, and I need to put small text about size 8 to 11 px on pictures. I found that text() method prints quite blurred text. And I could not get clear text chosing different values for methods font, font_family, font_style, font_weigth.

I attached a picture. In the left of it you can see what RMagick generates for me and in the right you can see the example of clear text I need RMagick to generate for me.

What can I do to get clear text. Any ideas?

Here is my code:

gc.stroke_width(1) gc.pointsize(10) gc.stroke('black') gc.font_style(Magick::NormalStyle) gc.font_weight(Magick::LighterWeight) gc.text(x,y, "12:00")

3

In my text drawing, I set stroke to transparent and fill to the desired text color. Also, you could try turning off antialiasing. I ended up using anti-aliasing, but rendering the text at double size and scaling down for acceptable results.

4

I tried to call / not to call methods fill() and stroke(). result is different in all cases:

gc.fill('black') #results in:

#gc.fill('black') # call is commented out gc.stroke('black') # results in:

Attachments: http://www.ruby-forum.com/attachment/2864/stroke_only.png

5

Zhoran Tvalve wrote:

Zhoran Tvalve wrote:

I tried to call / not to call methods fill() and stroke(). result is different in all cases:

gc.fill('black') #results in:

#gc.fill('black') # call is commented out gc.stroke('black') # results in:

gc.fill('black') gc.stroke('black') # calling both results in:

Сomparing these three pictures you can see, that calling both methods stroke() and fill() makes best picture, but I still need better. Something like at attached picture (I used pixel editor :slight_smile: to prepare it)

And It seems to me that scaling down could not make accurate symbols.

Attachments: http://www.ruby-forum.com/attachment/2866/needed.png

6

I would have something like:

gc.stroke('transparent').stroke_antialias(false) gc.fill('black')

The stroke_width setting won't have any effect on the text. I also never saw any variation from using the font_style or font_weight settings. I'm not sure if turning off antialiasing has any effect on text, since I now have that commented out in my code. I still turn off antialiasing when drawing lines because I only draw rectangles. On an angled line you might need it.

The font you choose may also have something to do with it. Run

convert -list font

at the command line to see the available fonts and families on your system.

Jim Crate Que Viva Development

7

Jim wrote:

I would have something like:

gc.stroke('transparent').stroke_antialias(false) gc.fill('black')

The stroke_width setting won't have any effect on the text. I also never saw any variation from using the font_style or font_weight settings. I'm not sure if turning off antialiasing has any effect on text, since I now have that commented out in my code. I still turn off antialiasing when drawing lines because I only draw rectangles. On an angled line you might need it.

The font you choose may also have something to do with it. Run

convert -list font

at the command line to see the available fonts and families on your system.

Jim Crate Que Viva Development

Hi, Jim! It really works!! I just turned off antialiasing and got it!!! Please take a look at the pictures. That is what I needed. Thank you for your help!

Attachments: http://www.ruby-forum.com/attachment/2873/1.png

8

Good luck, Jim :wink:

Attachments: http://www.ruby-forum.com/attachment/2874/2.png

9

Zhoran Tvalve wrote:

Hi, Jim! It really works!! I just turned off antialiasing and got it!!! Please take a look at the pictures. That is what I needed. Thank you for your help!

One note more. I've checked again and found that result defends on both callings @gc.stroke('transparent').stroke_antialias(false) @gc.text_antialias = false

the best result (which I showed upper) produced by calling both methods.

10

hmm...I never noticed the text_antialias method before. I'll have to remember that the next time I run into issues.

Glad I could help!

Jim

11

You can use this article on Image Manipulation to clear your query. This article may prove to be of your help.