Tuesday 1 March 2011

Hue/Saturation, Level, Curve...What's That?

Hari ini seperti yang dijadualkan dalam Course Outline, Dr Zaida akan mengajar mengenai fungsi Hue/Saturation, Level dan Curve...

Jadi ini merupakan quick definition bagi term-term tersebut.

i. Brightness/Contrast
Brightness digunakan untuk mengatur kecerahan gambar manakala Contrast digunakan untuk ketajaman gambar. Ini telah pun ditunjukkan oleh Dr Zaida menggunakan gambar daun pada minggu lepas


ii.Hue/Saturation
Hue adalah warna manakala Saturation adalah ketebalan/nipisnya warna tersebut. Kedua-duanya digunakan untuk menggantikan warna tertentu pada gambar/seleksi  


iii. Level
Level adalah seperti Brightness/Contrast tetapi lebih fleksibel kerana warna gelap, warna menengah dan warna terang dapat diatur dengan baik.


iv. Curve
Curve adalah seperti Level cuma warna RGB nya sahaja diaturkan di dalam bentuk curve.


Things to reflect !!!

1. Why it is advisable to use Level/Curve compared to Brightness/Contrast?

2. Figure 2A is a picture of model trucks and cars.  It is desired to change the color of the bulldozer from yellow to green.  Using the Hue/Saturation adjustment seen in Figure 1, the Edit drop down box was changed to Yellows.  Then the eyedropper tool, circled in red in Figure 1, was selected and clicked on the bulldozer only.  The Hue slider was then moved to the right until the desired color was achieved.  In this case, +62.  However, as seen in Figure 2B, the car was also changed to green.

Why did the color of the car change when the eyedropper was only clicked on the bulldozer?

 
Figure 2A


 
Figure 2B

Figure 1

Simply download the picture to test them yourselves.

Please make the reflection and share your opinion with others. And i will upload the answer later. Hopefully by doing the exercise will strengthen your skills in Photoshop...
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10 comments:

  1. Zaida2 March 2011 at 09:49

    why... we should use level/curve instead of brightness and contrast... please reflect here and also in your blog...

    ReplyDelete
  2. kay_adam3 March 2011 at 16:03

    1. Level/Curve bekerja dalam level dan boleh mengatur warna RGB secara spesifik dan boleh adjustkan terang gelap dengan bahagian yang kita kehendaki sahaja dengan menggunakan level/curve.

    Brightnes/Contrast hanya untuk edit terang gelap secara keseluruhan gambar tersebut.

    2. Ini adalah kerana eyedropper tool digunakan untuk "marking" warna bukannya objek. Ini bererti apabila kita klik eyedropper tools pada bulldozer maka warna kuning yang telah di "marking". Apabila kita buat perubahan warna +62 maka warna kuning akan berubah jadi hijau pada bulldozer dan kereta pun akan turut sama akan berubah. Kesimpulannya dengan menggunakkan eyedropper tools dalam Hue/Saturation gambar-gambar yang sama warna boleh diubah sekali dalam masa serentak.

    Dr boleh rujuk blog...

    ReplyDelete
  3. Zaida3 March 2011 at 21:13

    TQVM Kadir..... yang lain mana ni

    ReplyDelete
  4. arichom5 March 2011 at 11:59

    Saya ada.. yang lain cuti kot..hehehe..

    Ermm semua kadir dah bagi tau..sama jer la.. TQVM Kadir..Dr Zaida pun...

    ReplyDelete
  5. Naza Digital Album5 March 2011 at 15:15

    hehehe..yang lain mane pulak cuti..jem la..

    Dr..hurmm same la mcm kadir ckp tu..

    ReplyDelete
  6. zune6 March 2011 at 22:01

    Q1:
    Level/curve able to be used to manage tone, contrast and the colour of specific area or specific colour. Brightness/contrast only able to adjust the brightness and the sharpness of the whole picture. Image only will look real if we only adjust the tone/brightness of specific area instead of change the brightness of whole image.

    Q2:
    When we have set the drop down box to “yellow” means we will change everything in the image which is in yellow colour. The car and the bulldozer are in yellow colour, when we change yellow to green both of car and bulldozer will change to green in the same time.

    ReplyDelete
  7. KHAIRUNISA MOHAMAD FAKRI23 March 2011 at 15:59

    ANSWER 1: Level is a lot faster than brightness and contrast, because everytime you adjust brightness you will have to readjust contrast and vice versa to get the range. With levels, you can set the darkest areas and lightest areas and then adjust midtone. Readjusting midtones does not require adjusting the black and white sliders, the way adjusting contrast or brightness would require going back and adjusting the other. Curves, are like graphic equalizers, and allow different weighting of different colour ranges. With curves, for example, you can brighten shadows without effecting midtones. That is why it is advisable to use level/curve rather than brightness / contrast.


    ANSWER 2: Color of the car is same with the color of bulldozer. So, when you apply eyedropper on bulldozer , it will automatically change the colour of the car.

    ReplyDelete
  8. Ivan11 April 2011 at 22:40

    the hue, level and curve are a very useful tool to change the color in an image. I like this technique alot.

    ReplyDelete
  9. Ivan13 April 2011 at 16:31

    Q1:
    Level/curve able to control all the color aspects and professional graphic designer prefer this adjustment as it is more flexible and high creativity. Brightness/contrast only able to adjust the brightness and the black/white of the whole picture.

    Q2:
    As we set Edit:“yellow”, we will change all the subject in yellow color to other color. The car and the bulldozer are in the same color, so it change as we make any adjustment.

    ReplyDelete
  10. Encik Cot28 April 2011 at 12:09

    nak jawab.. semua jawapannya adalah sama seperti di atas.

    tapi sekurang2nya sekarang saya tau kenapa kena guna level/curves berbanding brightness/contrast.

    dan sekarang saya tau macam mana nak tukarkan warna yang sama secara serentak... (dah nak exam esok baru nak wat reflek..)

    ReplyDelete

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