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Convert Picture to Sketch Drawing

I wanted to create some art, but I lacked the skill, time, and materials to make it. So I wrote computer programs that could do it for me.

Baby swan photo to sketch.

Baby swan photo to sketch.

Photo to Drawing

An unedited photo is a fairly accurate representation of what you saw. It is a very realistic 2D copy of a moment in time. When you take a photo you usually want it to do a good job of matching the colors.

Digital camera pictures are made up of millions of tiny square dots with red, green, and blue color values. These dots can be a million different colors. Handmade drawings are often made with a single pencil. They are gray or black and contain hundreds of lines.

After taking a photo you might want to turn it into a drawing. You can try to recreate the original photograph by drawing on a piece of paper using a pencil or on a screen using a computer pen. An easier way is to load an image and press a button.

People like to look at drawings and turning your camera photos into art is a good way to create new content. If you are not using filters and effects on your pictures then you are missing out on the opportunity to transform them into something else.

I started making art by loading a photo, pressing a button and waiting for the computer program to finish. Sometimes I would need to wait 20 minutes. Recently I figured out how to create a quick sketch effect. It was so fast that I did not need to wait.

Quick Sketches

When searching for sketches using Google you end up with outline images, line drawings and grayscale pictures. According to search results a sketch could be an unfinished drawing, a picture made with a single color, or a rough draft.

An outline drawing shows the basic form without shading. It lacks detail, most of the image may be blank and it looks unfinished. A quick sketch can look as good as finished drawing that took hours to make.

I made outline drawings by using a grayscale filter, making an inverted copy, blurring the copy and then merging them together. It is simple and fast. Keep increasing the blur and it gradually fills in the canvas. Stop when it is filled in enough.

Edge detection tries to detect the edges by comparing the colors. If the colors are different enough then it draws the pixels. The result is an image that is not filled in. Changing the maximum difference between colors allows you to reduce or increase the number of visible lines.

Sketches often look better when some of the darker areas are filled in. Eyes tend to look weird as empty circles. You may want to fill in the areas that were black.

Other Methods

AI Style Transfer

Another way to convert a picture into a sketch is to remake it in the style of another image. Select the picture you want to convert. Then load a style image that looks like a sketch. Transfer the style and see what you end up with.

I used AI style transfer to turn ordinary photos into digital art. It can give you some interesting results. Do it in the style of an outline drawing and your photo is converted into an outline drawing. You could use the images on this page as the style.

The main advantage of using AI style transfer is that the number of styles is nearly unlimited. While I was experimenting, I did a single photo in 50 different styles.

Line Drawing

An app can create lines based on color values. It uses the color information and location of a pixel to see if a pixel should be added to the line. The individual lines can be visible or they may blend together.

Using random lines allows you to stop before it is finished. The app randomly places lines. Then you choose when to save or stop it. At first the image may not look like anything. Non random drawings can give you darker areas and more contrast but it takes longer because you need to wait for it to finish.

Short lines can give you a more accurate representation. It looks like the artist took their time. They were careful and meticulous. Use long lines and it looks more like a quick sketch.

Lines can be vertical, horizontal or diagonal. The direction you use matters, especially when all the lines have similar angles. The horizontal version may look better than the vertical version and vice versa. When using a computer to do the hard work for you, test out different options.

To create a sketch I used long random lines and stopped before it was finished. Pick a picture with dark and light areas that has a lot of contrast. You could increase the amount of white space by using image filters or erasing parts of the image before starting the line drawing.

Color Reduction

Drawing a photo using a limited number of colors from a list allows you to reduce the number of colors. Reducing the number of colors is a good way to convert a picture you took with your phone into a painting or drawing. I remade a photo using colors from a crayon box.

Using a grayscale filter just makes it look like a grayscale photograph. Reduce the number of colors first to simplify the image and you may be able to make it look like a pencil sketch.

Digital photo to simple wolf sketch

Digital photo to simple wolf sketch

Public Domain Images

There are lots of public domain photographs that make good sketches. The problem is that the outline drawings you make with a public domain image may look identical to sketches that were made by somebody else.

People tend to post duplicate content when a filter or effect is simple, quick and very easy to use. For example, hundreds of invisible challenge videos on TikTok that are nearly identical. To create original content try to use pictures that were not already turned into digital sketch drawings or find another way to make them unique.

Doing a Google image search and searching by image is a good way to find out if you are making duplicate content. Search for your picture and see if you get any results. Then scroll down and look at the visually similar images.

Half of the pictures on this page were made from a public domain photo but my digital art is not in the public domain. When you make something original from a public domain picture, you own the copyright to the new version if the changes are significant.

Deer sketch from a photograph using edge detection.

Deer sketch from a photograph using edge detection.

Is a realistic drawing better than a quick sketch?

Sometimes it looks like the artist used a grayscale filter on a photograph. If the pencil lines were obvious I might not see them while viewing the image at a smaller size.

Creating photorealistic pictures from a photograph may seem like a waste of time and you are creating duplicate content. Do the image by hand and it is very impressive but it may not get more views or likes than the photograph. Use a computer program and you are just making a copy that is slightly different than the original.

When you are making a copy, realistic drawings are not unique. It is usually better to make unrealistic copies. A quick sketch is better than something that looks like a camera photo. Highly realistic drawings may be better when they are not based on a photo or they are more artistic.

You can create unique original art by doing a single picture in different styles. If you are a skilled artist or you are using a computer program, I recommend converting a photo to a finished drawing and a sketch.

Photo to Sketch App

The pictures on this page were made using my photo to quick sketch app. First I did some research and figured out how to quickly create a sketch effect by making an inverted copy and then merging both images. Then I converted my favorite photos into outline drawings.

For the effect to work you need to blur the inverted copy. I did not want to guess or experiment by entering different blur value. So I set the program to gradually increase the blur. Watch the app make a drawing. Stop it when it is filled in enough.

Some of the results were too dull and faded. So I added an Intensify option to make the lines darker. Others were too dark so I added an Opacity option. Reducing the opacity can make it look more like a pencil sketch.

The results were similar to using edge detection. So I added an Edges option that creates an outline image by detecting the edges.

Moose photo to sketch.

Moose photo to sketch.

My Results

I quickly converted all of my favorite photos into sketches. It was faster and easier than turning them into drawings. Since it is faster you can convert more pictures and experiment.

The images still look like a sketch when viewed at a smaller size and they stand out. I like that the sketches I made on my laptop look good on a phone screen. In my opinion the digital art on this page is simple but fascinating. It captures your attention.

The downside is that there are fewer ways to turn a photograph into a great looking sketch. Simplifying the image limits your options. You may only be able to create 3 or 4 unique sketches from a single photo that are Pinterest or Twitter worthy.

If you use a computer app to convert a popular public domain photograph into a sketch then it will probably look similar, or identical to a sketch made by someone else. When possible, use pictures you took with your phone or digital camera so you are not accidentally creating duplicate content.

Turning photos into sketches is easy and fast. The hard part taking a great picture.

Outline drawing of my dog.

Outline drawing of my dog.

Resources

  • How to Make AI-Generated Art With Style Transfer
    Create non-photorealistic images by combining the subject of the first picture with the style of the second. Making AI-generated art is fun, and the results are impressive and interesting to look at.
  • How to Convert a Photo to Scribble Line Drawing Art
    Learn how to create interesting sketches and drawings that stand out. Making pictures with thin visible lines can give you some interesting results. Draw them yourself or turn an image into line art using a computer program.
  • How to Make Digital Art Look Traditional
    Does it look like you used the latest app with virtual paint brushes and virtual pencils? Sometimes you want your digital art to look handmade or vintage. Learn how to make art on your computer that looks traditional.
  • How to Make Digital Art From Photos Without Drawing
    Convert photos to digital art at the touch of a button. You don't need to manually draw, paint, or type to create the artwork—a computer program can do the hard work for you.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2022 Michael H